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1.
Article in Chinese | MEDLINE | ID: mdl-37805747

ABSTRACT

Burn induced coagulopathy (BIC) is one of the common complications after burn injury. The types and clinical manifestations of BIC vary dramatically, which frequently leads serious consequences. However, at present BIC does not attract enough attention in clinic. In order to prevent and treat BIC more effectively, the authors suggest that it is necessary to strengthen coagulation surveillance, operation management, infection control, rational application of drugs, prevention and treatment of deep vein thrombosis, relative clinical and basic research, and others.


Subject(s)
Blood Coagulation Disorders , Burns , Humans , Blood Coagulation Disorders/etiology , Blood Coagulation Disorders/therapy , Burns/complications , Burns/therapy
3.
Zhonghua Yi Xue Za Zhi ; 103(23): 1739-1745, 2023 Jun 20.
Article in Chinese | MEDLINE | ID: mdl-37305932

ABSTRACT

Objective: To explore the effect of blood lipids on the lesion distribution pattern in patients with acute ischemic stroke by using MRI technology based on population standard spatial analysis. Methods: The MRI data of 1 202 patients with acute ischemic stroke in General Hospital of Eastern Theater Command from January 2015 to December 2020 and Nanjing First Hospital from January 2013 to December 2021 were retrospectively collected, including 871 males and 331 females, aged 26 to 94 (64±11) years. According to the condition of blood lipids, they were divided into the dyslipidemia group (n=683) and the normal blood lipids group (n=519). After the automatic segmentation of diffusion-weighted imaging (DWI) images by artificial intelligence, the infarct sites were registered to the standard space which was used to draw the frequency heat map. The chi-square test was used to compare the difference in lesion location between the two groups. Generalized linear model regression analysis was used to observe the correlation between each blood lipid index and lesion site, and inter-group comparison and correlation analysis were used to observe the relationship between each blood lipid index and lesion volume. Results: Compared with the normal blood lipid group, the lesions in the dyslipidemia group were more extensive, mostly distributed in the occipital temporal region of the right posterior cerebral artery and the frontal region of the left middle cerebral artery. The brain regions of higher triglyceride(TG) and higher low-density lipoprotein cholesterol(LDL-C) groups were concentrated in the posterior circulation. The brain regions in the higher total cholesterol(TC) and lower high-density lipoprotein cholesterol(HDL-C) groups were concentrated in the anterior circulation(all P<0.05). In the anterior circulation infarct volume, the higher TC group was significantly higher than the normal TC group[(27.58±5.34) vs (17.73±1.18)ml, P=0.029]. In the posterior circulation infarct volume, the higher LDL-C group and the TG group were significantly higher than the normal LDL-C and TG groups[(7.55±2.51) vs (3.55±0.31) ml; (5.76±1.19) vs (3.36±0.30) ml](both P<0.05). Correlation analysis showed that TC and LDL-C were non-linearly (U-shaped) correlated with anterior circulation infarct volume (both P<0.05). Conclusions: Different blood lipids have effects on the distribution pattern and volume of ischemic stroke infarcts. Different hyperlipidemia is related to the specific distribution site and the larger extent of infarction.


Subject(s)
Anterior Wall Myocardial Infarction , Ischemic Stroke , Female , Male , Humans , Artificial Intelligence , Cholesterol, LDL , Retrospective Studies , Lipids , Magnetic Resonance Imaging
4.
Zhonghua Yi Xue Za Zhi ; 103(11): 842-849, 2023 Mar 21.
Article in Chinese | MEDLINE | ID: mdl-36925118

ABSTRACT

Objective: To explore the predictive performance of image quantitative index model, clinical-laboratory index model and image-clinical multi-dimensional fusion model in predicting the prognosis of patients with aneurysmal subarachnoid hemorrhage (aSAH) with intraventricular hemorrhage (IVH). Methods: A total of 349 patients with aSAH and IVH, including 122 males and 227 females, aged 22 to 85 (59±11) years underwent CT scan in the General Hospital of Eastern Theater Command from January 2010 to December 2019 were used as dataset 1 to construct a prognostic model. A prognostic model was constructed for data set 1, and the functional recovery of patients 12 months after discharge was evaluated using the modified Rankin Scale (mRS). According to the results, those patients were divided into two groups: good outcome group (n=267) and poor outcome group (n=82). In addition, 63 aSAH patients with IVH, including 27 males and 36 females, aged 32 to 87 (61±12) years who were admitted to the General Hospital of Eastern Theater Command from January 2020 to December 2021 were collected as dataset 2 for independent verification of the model, including 30 patients with poor prognosis. Clinical information (age and gender), laboratory indicators (blood routine and blood biochemistry), and imaging quantitative indicators (such as volume, density, shape of each ventricle hemorrhage area outlined and extracted on head CT scan etc.) were recorded for all patients (dataset 1 and 2). The clinical, laboratory and imaging quantitative indicators of dataset 1 were screened by using L1 regularization and multiple logistic regression method was used to construct the clinical-laboratory index model, image quantitative index model and image-clinical multi-dimensional fusion model, according to the weight coefficient of features in the clinical-laboratory index model and image quantitative index model, screen out the main features. The model was trained and internally validated by 5-fold cross-validation. The model was validated independently in dataset 2. Results: The AUC (area under the ROC curve) of clinical-laboratory index model, image quantitative index model and multidimensional fusion model constructed based on dataset 1 were 0.75 (95%CI: 0.69-0.81), 0.68 (95%CI: 0.61-0.74) and 0.86 (95%CI: 0.82-0.91). The Delong test showed that there were statistically significant differences between the performance of the multi-dimensional fusion model and the clinical-laboratory index model or image quantitative index model (all P<0.05). The AUC of clinical-laboratory index model, image quantitative index model and multidimensional fusion model of dataset 2 were 0.79 (95%CI: 0.68-0.91), 0.70 (95%CI: 0.57-0.83) and 0.81 (95%CI: 0.70-0.92). In addition, in the clinical-laboratory index model and imaging quantitative index model constructed based on data 1, age, Hunt-Hess grade on admission, Neutrophil/Lymphocyte (N/L) (the weight coefficients in the clinical-laboratory index model were 1.00, -0.59 and 0.44) and the standard deviation of third ventricle hemorrhage density, minimum hemorrhage density of the fourth ventricle, and left ventricle hemorrhage sphericity (the weight coefficients in the image quantitative index model were -1.00, 0.85 and -0.84) were the main features of the screening. Conclusions: Quantitative imaging indicators of ventricular hemorrhage (standard deviation of third ventricular hemorrhage density, minimum density of fourth ventricular hemorrhage, and left ventricular sphericity) are helpful to predict the poor prognosis of patients with aSAH with ventricular hemorrhage. Dimensional fusion model has greater value in predicting poor prognosis of patients.


Subject(s)
Subarachnoid Hemorrhage , Male , Female , Humans , Subarachnoid Hemorrhage/diagnostic imaging , Prognosis , Cerebral Hemorrhage/diagnostic imaging , Tomography, X-Ray Computed , Lymphocytes , Retrospective Studies
5.
Zhonghua Shao Shang Za Zhi ; 38(10): 914-922, 2022 Oct 20.
Article in Chinese | MEDLINE | ID: mdl-36299202

ABSTRACT

Objective: To explore the effect of P311 microspheres-loaded thermosensitive chitosan hydrogel on the wound healing of full-thickness skin defects in rats. Methods: The method of experimental study was adopted. The polyvinyl alcohol/sodium alginate microspheres (simple microspheres), P311 microspheres, and bovine serum albumin labeled with fluorescein isothiocyanate (FITC-BSA) microspheres were prepared by water-in-oil emulsification, and then their morphology was observed under a light microscope/inverted fluorescence microscope. Chitosan solution was prepared, chitosan solution and ß-glycerol phosphate disodium hydrate were mixed to prepare simple thermosensitive hydrogels, and thermosensitive hydrogels loaded with simple microspheres or P311 microspheres were prepared by adding corresponding substances in simple thermosensitive hydrogels. The morphological changes of the prepared four liquids in the state of tilt was observed at 37 ℃. After being freeze-dried, the micromorphology of the prepared four liquids was observed under a scanning electron microscope. Eighteen 3-4-week-old male Sprague-Dawley rats were divided into normal group without any treatment, dressing group, chitosan group, hydrogel alone group, simple microspheres-loaded hydrogel group, and P311 microspheres-loaded hydrogel group, which were inflicted with one full-thickness skin defect wound on both sides of the back spine and were dealt correspondingly, with 3 rats in each group. Rats with full-thickness skin defects in the five groups were collected, the wound healing was observed on post injury day (PID) 0 (immediately), 5, 10, and 15, and the wound healing rates on PID 5, 10, and 15 were calculated. The wound and wound margin tissue of rats with full-thickness skin defects in the five groups on PID 15 and normal skin tissue in the same site of rats in normal group were collected, hematoxylin and eosin staining was conducted to observe the histological changes, immunohistochemical staining was performed to observe the expressions of CD31 and vascular endothelial growth factor (VEGF), and Western blotting was conducted to detect the protein expressions of CD31 and VEGF. The number of samples was all three. Data were statistically analyzed with one-way analysis of variance, analysis of variance for repeated measurement, and Bonferroni correction. Results: Simple microspheres were spherical, with loose and porous surface. The surfaces of P311 microspheres and FITC-BSA microspheres were smooth without pores, and the FITC-BSA microspheres emitted uniform green fluorescence. The diameters of the three microspheres were basically consistent, being 33.1 to 37.7 µm. Compared with chitosan solution and simple thermosensitive hydrogel, the structures of the two microspheres-loaded hydrogels were more stable in the state of tilt at 37 ℃. The two microspheres-loaded hydrogels had denser network structures than those of chitosan solution and simple thermosensitive hydrogel, and in the cross section of which microspheres with a diameter of about 30 µm could be seen. Within PID 15, the wounds of rats in the five groups were healed to different degrees, and the wound healing of rats in P311 microspheres-loaded hydrogel group was the best. On PID 5, 10, and 15, the wound healing rates of rats in dressing group and chitosan group were (26.6±2.4)%, (38.5±3.1)%, (50.9±1.5)%, (47.6±2.0)%, (58.5±3.6)%, and (66.7±4.1)%, respectively, which were significantly lower than (59.3±4.8)%, (87.6±3.2)%, (97.2±1.0)% in P311 microspheres-loaded hydrogel group (P<0.05 or P<0.01). The wound healing rates of rats in hydrogel alone group on PID 10 and 15, and in simple microspheres-loaded hydrogel group on PID 15 were (76.0±3.3)%, (84.5±3.6)%, and (88.0±2.6)%, respectively, which were significantly lower than those in P311 microspheres-loaded hydrogel group (P<0.05). The epidermis, hair follicles, and sebaceous glands could be seen in the normal skin of rats in normal group, without positive expressions of CD31 or VEGF. The wounds of rats in P311 microspheres-loaded hydrogel group on PID 15 were almost completely epithelialized, with more blood vessels, hair follicles, sebaceous glands, and positive expressions of CD31 and VEGF in the wounds than those of rats with full-thickness skin defects in the other four groups, and more protein expressions of CD31 and VEGF than those of rats in the other five groups. Conclusions: The P311 microspheres-loaded thermosensitive chitosan hydrogel can release the encapsulated drug slowly, prolong the drug action time, and promote wound healing in rats with full-thickness skin defects by promoting wound angiogenesis and re-epithelialization.


Subject(s)
Chitosan , Skin Abnormalities , Soft Tissue Injuries , Rats , Male , Animals , Hydrogels , Vascular Endothelial Growth Factor A , Chitosan/pharmacology , Serum Albumin, Bovine/pharmacology , Microspheres , Polyvinyl Alcohol/pharmacology , Hematoxylin/pharmacology , Eosine Yellowish-(YS)/pharmacology , Rats, Sprague-Dawley , Wound Healing , Skin/injuries , Water/pharmacology , Alginates/pharmacology
6.
Zhonghua Shao Shang Za Zhi ; 37(11): 1024-1035, 2021 Nov 20.
Article in Chinese | MEDLINE | ID: mdl-34794254

ABSTRACT

Objective: To study the effects of reactive oxygen species (ROS)-responsive antibacterial microneedles (MNs) on the full-thickness skin defect wounds with bacterial colonization in diabetic mice. Methods: Experimental research methods were adopted. The ROS-responsive crosslinker N1-(4-boronobenzyl)-N3-(4-boronophenyl)-N1, N1, N3, N3-tetramethylpropane-1,3-diaminium (TSPBA) was first synthesized, and then the polyvinyl alcohol (PVA)-TSPBA MNs, PVA-ε-polylysine (ε-PL)-TSPBA MNs, PVA-TSPBA-sodium hyaluronate (SH) MNs, and PVA-ε-PL-TSPBA-SH MNs were prepared by mixing corresponding ingredients, respectively. The PVA-TSPBA MNs were placed in pure phosphate buffer solution (PBS) and PBS containing hydrogen peroxide, respectively. The degradation of MNs immersed for 0 (immediately), 3, 7, and 10 days was observed to indicate their ROS responsiveness. The standard strains of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) cultured in Luria-Bertani medium containing hydrogen peroxide were divided according to the random number table (the same grouping method below) into blank control group (without any treatment, the same below) and 0 g/L ε-PL group, 1.0 g/L ε-PL group, 5.0 g/L ε-PL group, and 10.0 g/L ε-PL group with which PVA-ε-PL-TSPBA MNs containing the corresponding concentration of ε-PL were co-cultured, respectively. Bacterial growth was observed after 24 h of culture, and the relative survival rate of bacteria was calculated (n=3). The mouse fibroblast cell line 3T3 cells at logarithmic growth stage (the same growth stage below) were divided into blank control group and 0 g/L ε-PL group, 1.0 g /L ε-PL group, 5.0 g /L ε-PL group, and 10.0 g /L ε-PL group in which cells were cultured in medium with the extract from PVA-ε-PL-TSPBA MNs containing the corresponding concentration of ε-PL, respectively. Cell growth was observed after 24 h of culture by optical microscopy, and the relative survival rate of cells was detected and calculated by cell counting kit 8 (CCK-8) assay to indicate the cytotoxicity (n=6). Both PVA-TSPBA MNs and PVA-TSPBA-SH MNs were taken, the morphology of the two kinds of MNs was observed by optical microscopy, and the mechanical properties of the two kinds of MNs were tested by microcomputer controlled electronic universal testing machine (denoted as critical force, n=6). Six male BALB/c mice aged 6-8 weeks (the same gender and age below) were divided into PVA-TSPBA group and PVA-TSPBA-SH group, with 3 mice in each group. After pressing the skin on the back of mice vertically with the corresponding MNs for 1 minute, the skin condition was observed at 0, 10, and 20 min after pressing. Another batch of 3T3 cells were divided into blank control group, 0 g/L ε-PL group and simple 5.0 g/L ε-PL group which were cultured with the extract of PVA-ε-PL-TSPBA MNs containing the corresponding concentration of ε-PL, and 5.0 g/L ε-PL+SH group which were cultured with the extract of PVA-ε-PL-TSPBA-SH MNs with 5.0 g/L ε-PL. The CCK-8 assay was performed to detect and calculate the relative survival rate of cells cultured for 24, 48, and 72 h to indicate the cell proliferation activity (n=6). Eighteen BALB/c mice were induced into diabetic mice model by high-sugar and high-fat diet combined with streptozotocin injection and then divided into sterile dressing group, 0 g/L ε-PL+SH group, and 5.0 g/L ε-PL+SH group, with 6 mice in each group. A full-thickness skin defect wound was made on the back of each mouse, and S. aureus solution was added to make a full-thickness skin defect wound with bacterial colonization model for diabetic mouse. The wounds of mice in 0 g/L ε-PL+SH group and 5.0 g/L ε-PL+SH group were covered with PVA-ε-PL-TSPBA-SH MNs with the corresponding concentration of ε-PL, and the wounds of mice in the 3 groups were all covered with sterile surgical dressings. The wound healing was observed on post injury day (PID) 0, 3, 7, and 12, and the wound healing rate on PID 3, 7, and 12 was calculated. On PID 12, the skin tissue of the wound and the wound margin were stained with hematoxylin and eosin to observe the growth of new epithelium and the infiltration of inflammatory cells. Data were statistically analyzed with one-way analysis of variance, analysis of variance for repeated measurement, Mann-Whitney U test, and Bonferroni test. Results: With the extension of the immersion time, the PVA-TSPBA MNs in PBS containing hydrogen peroxide gradually dissolved and completely degraded after 10 days of immersion. The PVA-TSPBA MNs in pure PBS only swelled but did not dissolve. After 24 h of culture, there was no growth of S. aureus in 5.0 g/L ε-PL group or 10.0 g/L ε-PL group, and there was no growth of E. coli in 10.0 g/L ε-PL group. The relative survival rate of S. aureus was significantly lower in 1.0 g/L ε-PL group, 5.0 g/L ε-PL group, and 10.0 g/L ε-PL group than in blank control group (P<0.05 or P<0.01). The relative survival rate of E. coli was significantly lower in 5.0 g/L ε-PL group and 10.0 g/L ε-PL group than in blank control group (P<0.01). After 24 h of culture, the cells in blank control group, 0 g/L ε-PL group, 1.0 g/L ε-PL group, 5.0 g/L ε-PL group, and 10.0 g/L ε-PL group all grew well, and the relative survival rate of cells was similar among the groups (P>0.05). The needle bodies of PVA-TSPBA MNs and PVA-TSPBA-SH MNs were both quadrangular pyramid-shaped and neatly arranged, and the needle bodies of PVA-TSPBA-SH MNs was more three-dimensional and more angular. The critical force of PVA-TSPBA-SH MNs was significantly higher than that of PVA-TSPBA MNs (Z=3.317, P<0.01). The MNs in PVA-TSPBA+SH group penetrated the skin of mice at 0 min after pressing, and the pinholes partially disappeared after 10 min and completely disappeared after 20 min, while the MNs in PVA-TSPBA group failed to penetrate the skin of mice. After 24, 48, and 72 h of culture, the proliferation activity of the cells in 5.0 g/L ε-PL+SH group was significantly higher than that of blank control group (P<0.05 or P<0.01). In sterile dressing group, the wounds of mice healed slowly and exuded more. The wound healing speed of mice in 0 g/L ε-PL+SH group was similar to that of sterile dressing group in the early stage but was faster than that of sterile dressing group in the later stage, with moderate exudation. The wound healing of mice in 5.0 g/L ε-PL+SH group was faster than that in the other two groups, with less exudation. The wound healing rates of mice in 5.0 g/L ε-PL+SH group were (40.6±4.2)%, (64.3±4.1)%, and (95.8±2.4)% on PID 3, 7, and 12, which were significantly higher than (20.4±2.7)%, (38.9±2.2)%, and (59.1±6.2)% in sterile dressing group and (21.6±2.6)%, (44.0±1.7)%, and (82.2±5.3)% in 0 g/L ε-PL+SH group (P<0.01). The wound healing rates of mice in 0 g/L ε-PL+SH group on PID 7 and 12 were significantly higher than those in sterile dressing group (P<0.05 or P<0.01). On PID 12, the wounds of mice in 5.0 g/L ε-PL+SH group were almost completely epithelialized with less inflammatory cell infiltration, the wounds of mice in 0 g/L ε-PL+SH group were partially epithelialized with a large number of inflammatory cell infiltration, and no obvious epithelialization but a large number of inflammatory cell infiltration was found in the wounds of mice in sterile dressing group. Conclusions: The composite MNs prepared by TSPBA, PVA, ε-PL, and SH can successfully penetrate mouse skin and slowly respond to ROS in the wound to resolve and release antibacterial substances, inhibit bacterial colonization, and promote the repair of full-thickness skin defect wounds with bacterial colonization in diabetic mice.


Subject(s)
Diabetes Mellitus, Experimental , Animals , Anti-Bacterial Agents/pharmacology , Escherichia coli , Male , Mice , Mice, Inbred BALB C , Reactive Oxygen Species , Staphylococcus aureus
7.
Zhonghua Yi Xue Za Zhi ; 101(37): 3024-3028, 2021 Oct 12.
Article in Chinese | MEDLINE | ID: mdl-34638195

ABSTRACT

Objective: To compare the hippocampal volume and local surface morphology changes in patients with mesial temporal lobe (mTLE) using the voxel-based morphometry and spherical harmonic methods respectively. Methods: A total of 66 patients (31 males and 35 females, age range from 17 to 48 (28±8) years) with mTLE and 80 age-and gender-matched controls (38 males and 42 females, age range from 19 to 46 (27±7) years) were retrospectively collected from July 2009 to February 2019 at Jinling hospital.. High resolution structural MRI of the whole brain, three-dimensional T1-weighted data(3DT1) were acquired from each subject. The changes of hippocampal volume and surface morphology were evaluated between mTLE groups and controls for observing the hippocampal atrophy pattern by using voxel-based morphometry and spherical harmonic shape descriptions point distribution model respectively. Pearson correlation analysis was conducted for observing the relationship between the morphological changes of hippocampus and disease duration. Results: Compared with the controls, hippocampal volume on the affected side in patients with mTLE was significantly reduced (Z-score:-1.55±0.57 vs 0.38±0.58, P<0.001) and negatively correlated with disease duration (r=-0.297, P=0.016). Furthermore, surface morphology analysis subtly showed that the atrophy of the affected hippocampus in patients with mTLE mainly located in the head, mesial lateral part and posterior tail of the hippocampus. Their displacement values were negatively correlated with disease duration (r=-0.336, P=0.006) and positively associated with the hippocampal grey matter volume (r=0.336, P=0.006). Conclusions: Voxel-based morphometry analysis reveals a global reduction in hippocampal volume, while the morphological measurement method based on surface shape can describe the local morphological changes of hippocampal atrophy.


Subject(s)
Epilepsy, Temporal Lobe , Adolescent , Adult , Epilepsy, Temporal Lobe/diagnostic imaging , Female , Hippocampus/diagnostic imaging , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Retrospective Studies , Temporal Lobe/diagnostic imaging , Young Adult
8.
Zhonghua Wei Chang Wai Ke Za Zhi ; 24(5): 413-419, 2021 May 25.
Article in Chinese | MEDLINE | ID: mdl-34000770

ABSTRACT

Objective: Endoscopic submucosal dissection (ESD) of undifferentiated early gastric cancer (UD-EGC) remains controversial due to high positive rate of horizontal and vertical resection margins and the risk of lymph node metastasis. The purpose of this study was to compare long-term outcomes of patients with UD-EGC undergoing ESD versus surgery. Methods: This study was a retrospective cohort study. Inclusion criteria: (1) patients with early gastric cancer undergoing ESD or surgical resection; (2) histological types included poorly differentiated adenocarcinoma, poorly differentiated adenocarcima with signet ring cell carcinoma, and signet ring cell carcinoma; (3) no lymph node metastasis or distant metastasis was confirmed by preoperative CT and endoscopic ultrasonography. Exclusion criteria: (1) previous surgical treatment for gastric cancer; (2) synchronous tumors; (3) death with unknown cause; (4) additional surgical treatment was performed within 1 month after ESD. According to the above criteria, clinical data of patients with UD-EGC who received ESD or surgery treatment in Cancer Hospital of Chinese Academy of Medical Sciences from January 2009 to December 2016 were collected. After further comparing the clinical outcomes between the two groups by 1:1 propensity score matching, 61 patients in the ESD group and 61 patients in the surgery group were finally included in this study. The disease-free and overall survivals were analyzed by Kaplan-Meier method. Results: All patients in the two groups completed operations successfully. In the ESD group, the median operation time was 46.3 (26.5, 102.3) minutes, 61 cases (100%) were en-bloc resection, and 57 cases (93.4%) were complete resection. Positive margin was found in 4 (6.6%) patients, of whom 2 were positive in horizontal margin and 2 were positive both in horizontal and vertical margins. In the surgery group, only 1 case had positive horizontal margin and no positive vertical margin was observed. There was no significant difference in the positive rate of margin between the two groups (P>0.05). Median follow-up time was 59.8 (3.0, 131.5) months. The follow-up rate of ESD group and surgery group was 82.0% (50/61) and 95.1% (58/61), respectively. The 5-year disease-free survival rate in ESD group and surgery group was 98.2% and 96.7%, respectively (P=0.641), and the 5-year overall survival rate was 98.2% and 96.6%, respectively (P=0.680). In the ESD group, 1 patient (1.6%) had lymph node recurrence, without local recurrence or distant metastasis. In the surgery group, 1 case (1.6%) had anastomotic recurrence and 1 (1.6%) had distant metastasis. Conclusion: ESD has a sinilar long-term efficacy to surgery in the treatment of UD-EGC.


Subject(s)
Endoscopic Mucosal Resection , Stomach Neoplasms , Gastric Mucosa , Humans , Neoplasm Recurrence, Local , Retrospective Studies , Stomach Neoplasms/surgery , Treatment Outcome
9.
Zhonghua Zhong Liu Za Zhi ; 42(9): 746-751, 2020 Sep 23.
Article in Chinese | MEDLINE | ID: mdl-32988157

ABSTRACT

Objective: To explore the short and long-term outcomes of endoscopic piecemeal mucosal resection including endoscopic mucosal resection (EMR) and multiband mucosectomy (MBM) for superficial esophageal carcinoma and precancerous lesions, and analyze the risk factors for prognosis. Methods: From March 1 2001 to May 31 2017, 371 patients with 416 lesions who were diagnosed as superficial esophageal carcinoma or high-grade intraepithelial neoplasm and underwent EMR or MBM were retrospectively enrolled in this study. Long-term recurrence free survival (RFS) rate and the risk factors, including submucosal invasion, poorly differentiation, vascular invasion and positive vertical margin, for the long-term outcome were also analyzed. Results: The incidence of complication was 17.1% in the EMR group and 17.4% in the MBM group, without significant difference (P=1.000). The median follow-up period was 70.6 months. The 5-years RFS was 93.9% and 10-years RFS was 87.8%, respectively. Local recurrence was found in 2 cases in each group and they were curatively treated by endoscopic submucosal dissection. Heterogeneous multiple primary esophageal cancer was diagnosed in 5 and 3 cases for the EMR and MBM group, of whom 5 cases were curatively treated with endoscopic resection. Other 3 cases were diagnosed with advanced esophageal cancer, of whom 2 patients died. Lymph node metastasis (LNM) was found in 5 cases in the EMR group and 4 cases in the MBM group, of whom 6 patients died. Distant metastasis was found in 5 cases in the EMR group and 3 cases in the MBM group, of whom 5 patients died. There were 83 patients combined with risk factors including submucosal invasion, poorly differentiation, vascular invasion and positive vertical margin, of whom 8 patients were diagnosed as LNM and 8 patients as distant metastasis. The 5-years RFS of patients with 1, 2, and 3 risk factors were 93.6%, 82.2%, and 25.0%, and the difference was statistically significant (P<0.001). Conclusions: EMR and MBM are both safe and feasible procedures for superficial esophageal carcinoma and precancerous lesions. Additional treatments should be selected according to the variety of risk factors to acquire better long-term outcome and life quality.


Subject(s)
Carcinoma , Endoscopic Mucosal Resection , Esophageal Neoplasms , Precancerous Conditions , Carcinoma/surgery , Esophageal Neoplasms/surgery , Esophagoscopy , Humans , Neoplasm Recurrence, Local , Precancerous Conditions/surgery , Retrospective Studies , Treatment Outcome
10.
Zhonghua Zhong Liu Za Zhi ; 42(9): 752-757, 2020 Sep 23.
Article in Chinese | MEDLINE | ID: mdl-32988158

ABSTRACT

Objective: To analyze the long-term therapeutic effect of endoscopic submucosal dissection (ESD) on the treatment of early gastric cancer (EGC). Methods: We retrospectively reviewed EGC patients who underwent ESD at Cancer Hospital, Chinese Academy of Medical Sciences (CAMS), from January 2009 to December 2016. The incidence rates of local recurrence, synchronous cancer and heterogeneous cancer were analyzed. Kaplan-Meier method was used to analyze 5-years recurrence free survival (RFS) and 5-years disease special survival (DSS) of all patients. Results: A total of 255 EGC patients were enrolled in this study, included 175 differentiated early gastric cancer (D-EGC) patients and 80 undifferentiated early gastric cancer (UD-EGC) patients. Among them, 171 patients within the extended indication of ESD while 84 patients beyond the extended indication of ESD. Among the 225 patients, the incidence rates of local recurrence, synchronous cancer and heterogeneous cancer were 2.0%, 2.0% and 2.4%, respectively. The local recurrence rates of D-EGC group and UD-EGC group was 1.7% and 2.5%, respectively, without significant difference (χ(2)=0.176, P=0.675). The incidence rates of synchronous and heterogenous cancer in the D-EGC group were 2.3% and 3.4%, higher than 1.2% and 0 of UD-EGC group, although there was no significant difference (χ(2)=0.306, P=0.580 vs χ(2)=2.809, P=0.094). There were no significant differences in 5-years RFS (91.3% vs 95.9%, P=0.236) and 5-years DSS (100% vs 98.6%, P=0.156) between D-EGC group and UD-EGC group. Conclusions: The long-term outcome of ESD in the treatment of EGS is good. More attention should be paid to the occurrence of local recurrence and heterogeneous cancer in EGC patients undergo ESD. These patients still have a good long-tern outcome even undergoing ESD for more than once.


Subject(s)
Endoscopic Mucosal Resection , Stomach Neoplasms , Gastric Mucosa , Humans , Neoplasm Recurrence, Local , Retrospective Studies , Stomach Neoplasms/surgery , Treatment Outcome
11.
Zhonghua Zhong Liu Za Zhi ; 42(9): 758-764, 2020 Sep 23.
Article in Chinese | MEDLINE | ID: mdl-32988159

ABSTRACT

Objective: To analysis the clinical and follow-up data of the early colorectal carcinoma (ECC) after endoscopic resection, and explore the long-term outcome of patients who underwent the endoscopic resection. Methods: During June 2008 to June 2016, data of endoscopic resection for 550 cases of ECC were collected, including general information and follow-up data. The influence factors of disease-free survival rate of ECC after endoscopic resection were analyzed and the risk factors on long-term outcomes such as submucosa invasion depth, poorly differentiated adenocarcinoma, vascular invasion and positive vertical margin were investigated. Results: The mean follow-up time of 550 patients treated with endoscopy was (60.7±36.8) months. Among them, 433 cases were high-level intra-mucosal neoplasia, 117 cases were submucosa invasion carcinoma (the invasion depth <1 000 µm were 33 cases, ≥1 000 µm were 84 cases), 461 cases were curative resection, while 89 cases were non-curative resection. During the follow-up, 6 patients occurred recurrence or metastasis, including 2 patients with local recurrence (1 patient accompanied by lymph node metastasis) and 4 patients with lymph node metastasis (2 patients accompanied by distant metastasis). The overall 5-years disease-free survival rate was 98.8%, the 5-years disease-free survival rate was 100.0% for patients with curative resection and 93.3% for patients with non-curative resection. A total of 89 cases underwent non-curative resection were accompanied with invasion depth ≥1 000 µm, vascular invasion, poorly differentiated adenocarcinoma and positive vertical margin. Among them, 62 cases were accompanied with 1 risk factor, 23 cases with 2 risk factors and 4 cases with 3 risk factors. The risks of lymph nodes and distant metastasis raised with the increase of risk factors. Conclusions: The incidence of lymph node metastasis in ECC is extremely low. Endoscopic treatment can achieve a good long-term outcome. Close follow-up should be conducted after endoscopic treatment, and additional treatment should be selected reasonably for the early colorectal carcinoma after endoscopic non-curative resection to improve the therapeutic efficacy of endoscopic resection.


Subject(s)
Adenocarcinoma , Colorectal Neoplasms , Adenocarcinoma/surgery , Colorectal Neoplasms/surgery , Humans , Lymphatic Metastasis , Neoplasm Invasiveness , Neoplasm Recurrence, Local , Retrospective Studies , Risk Factors , Treatment Outcome
12.
Zhonghua Yi Xue Za Zhi ; 100(27): 2121-2125, 2020 Jul 21.
Article in Chinese | MEDLINE | ID: mdl-32689753

ABSTRACT

Objective: To investigate the effect of febrile convulsions on gray matter volume (GMV) in medial temporal lobe epilepsy (mTLE) and its correlation with disease duration. Methods: A retrospective study was conducted to collect 41 mTLE patients with a history of febrile convulsions (mTLE-FC), 42 mTLE patients with no initial precipitating injury (mTLE-noIPI), and 42 normal and age and sex matched normal controls. High-resolution T1-weighted (T(1)WI) whole brain MR scans were performed on all subjects. Voxel-based morphometry were used to obtain GMV brain maps, and the GMV differences between the three groups of subjects were compared (P<0.01, GRF corrected). Finally, Spearmen rank correlation analysis was used to explore the correlation between GMV changes and the course of disease. Results: Compared with the normal control subjects, each mTLE group showed extensive GMV reduction, mainly in the affected hippocampus, thalamus, temporal lobe, and bilateral cerebellum. Further analysis found that mTLE-FC group had more significant reductions in GMV than the mTLE-noIPI group in the affected hippocampus, amygdala, inferior temporal gyrus, contralateral hippocampus, para hippocampus, and inner cingulate gyrus. At the same time, the affected amygdala and hippocampal GMV in the mTLE-FC group was significantly negatively related to the course of disease (r=-0.381, P=0.014), while the mTLE-noIPI group had no downward trend (r=0.081, P=0.611). The atrophic trend of the affected amygdala and hippocampus in patients with mTLE-FC was significantly greater than that in patients with mTLE-noIPI (P=0.029, permutation test). Conclusions: There is extensive damage to the gray matter structure of bilateral cerebral hemispheres, mainly in the hippocampus, in mTLE patients. The brain damage of mTLE patients with a history of juvenile fever convulsions is more extensive and serious, and the trend of progressive exacerbation with the course of the disease is more obvious, suggesting mTLE associated with juvenile fever convulsions may have different pathophysiological mechanisms.


Subject(s)
Epilepsy, Temporal Lobe , Seizures, Febrile , Adolescent , Brain , Hippocampus , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Retrospective Studies
13.
Zhonghua Jie He He Hu Xi Za Zhi ; 41(12): 942-948, 2018 Dec 12.
Article in Chinese | MEDLINE | ID: mdl-30522191

ABSTRACT

Objective: To investigate the characteristics of respiratory viral infections, and correlation between inflammatory cytokines and respiratory virus infections in patients with acute exacerbations of chronic obstructive pulmonary disease (COPD). Methods: A prospective cohort of patients with acute exacerbations of COPD was enrolled. The sputum of all patients were collected, and 15 respiratory viruses were detected using multi-channel real-time fluorescence quantitative PCR. The clinical characteristics associated with viral infections were analyzed. The peripheral blood of the patients was collected and cytokines including IL-6, IL-8, RANTES, IP-10, sIL-2R, IFN-γ, TNF-α in the serum were detected by ELISA. Association of these cytokines with respiratory viral infections was evaluated and a discriminant model was established. Results: A total of 99 patients with acute exacerbations of COPD were enrolled in this study. Thirty-four cases (34.3%, 34/99) were positive for viral detection. Among them, the positive rate of influenza A virus was the highest (38.2%, 13/34), followed by rhinovirus (35.3%, 12/34). Multifactor logistic regression analysis showed that, fever, COPD assessment test (CAT) score in stable stage, serum IP-10 and TNF-α levels were correlated with respiratory viral infections in patients with acute exacerbations of COPD. The levels of serum IP-10 and sIL-2R increased significantly in patients with influenza A virus. Conclusions: Respiratory viral infections were common in acute exacerbations of COPD. Influenza A virus and rhinovirus were the two most common viruses. Fever was a common symptom. Patients with severe respiratory symptoms at stable stage were susceptible to viral infection. Viral infection was associated with an increase in systemic inflammatory levels, most significantly in influenza virus infection. A discriminant model composed of fever, CAT score in stable stage, serum IP-10 and TNF-α levels can be used to predict respiratory viral infections in acute exacerbations of COPD.


Subject(s)
Cytokines , Inflammation Mediators/metabolism , Inpatients , Pulmonary Disease, Chronic Obstructive/immunology , Pulmonary Disease, Chronic Obstructive/virology , Respiratory Tract Infections/immunology , Virus Diseases/complications , Acute Disease , Humans , Prospective Studies , Pulmonary Disease, Chronic Obstructive/diagnosis , Respiratory Tract Infections/diagnosis , Respiratory Tract Infections/virology , Virus Diseases/diagnosis , Virus Diseases/immunology
14.
Zhonghua Jie He He Hu Xi Za Zhi ; 41(2): 95-99, 2018 Feb 12.
Article in Chinese | MEDLINE | ID: mdl-29429214

ABSTRACT

Objective: To evaluate the correlation between N-terminal probrainnatriuretic peptide (NT-proBNP) and the prognosis of death in hospitalized patients with acute exacerbation of chronic obstructive pulmonary disease(COPD). Methods: A cohort study of 169 patients with acute exacerbations COPD. According to the age and NT-proBNP value measured on admission, cases were divided into 3 groups. The risk ratio of mortality among the three group were analyzed. Results: Thirty-two patients died within 1 year. There are 93 cases in group A (NT-proBNP < 300 ng/L), 45 cases in group B (aged 75 and below with NT-proBNP 300-900 ng/L, older than 75 with NT-proBNP 300-1 800 ng/L), 31 cases in group C (aged 75 and below with NT-proBNP>900 ng/L, older than 75 with NT-proBNP>1 800 ng/L); The in-hospital mortalities were 3.2%, 11.1% and 32.3%respectively, and mortalities within a year were 5.4%, 17.8% and 61.3% . The risk ratio (RR) and 95%CI for dying in hospital of group C to group A and B were 10.00 (3.61-56.50) and 2.90 (1.15-12.60), RR and 95%CI for dying within 1 years after hospitalization were 11.40 (8.78-88.46) and 3.45 (2.56-20.97, P<0.05). Conclusion: The NT-proBNP values measured at admission were associated with the short-term and long-term prognosis of patients with AECOPD.


Subject(s)
Hospital Mortality , Natriuretic Peptide, Brain/blood , Peptide Fragments/blood , Pulmonary Disease, Chronic Obstructive/blood , Pulmonary Disease, Chronic Obstructive/mortality , Acute Disease , Aged , Biomarkers/blood , Cohort Studies , Humans , Prognosis , Pulmonary Disease, Chronic Obstructive/diagnosis
15.
Beijing Da Xue Xue Bao Yi Xue Ban ; 49(6): 979-984, 2017 Dec 18.
Article in Chinese | MEDLINE | ID: mdl-29263468

ABSTRACT

OBJECTIVE: To evaluate the ability of 2015 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) classification criteria to diagnose gout compared with the widely used 1977 American Rheumatism Association (ARA) criteria and other criteria in clinical practice in Chinese patients, and to compare the sensitivity and specificity of different classification criteria for gout in early and established diseases. METHODS: The patients who had ankle arthritis and visited the Department of Rheumatology and Clinical Immunology, Peking University First Hospital between February 2012 and February 2016 were screened. The patients who had been already diagnosed with gout or pyrophosphate deposition disease through arthrocentesis or tissue aspiration and those who had been diagnosed with rheumatoid arthritis, spondyloarthritis, and osteoarthritis were excluded. The patients were diagnosed by two experienced rheumatologists and all of them were followed up for at least one year. Early disease was defined as symptom onset of no more than 2 years; established disease was defined as symptom duration of more than 2 years. The 2015 ACR classification criteria were divided into clinical form with clinical parameters included and complete form with not only clinical parameters but also synovial fluids tests, imaging findings and monosodium urate (MSU) included. The two forms above were short for "clinical form (incorporating clinical parameters)" and "complete form (incorporating imaging and MSU data)" respectively. RESULTS: In this study, 284 patients suffering from ankle arthritis were inclu-ded in the study, 219 of them were classified as gout and 65 of them had alternative diagnoses. The sensitivity and specificity of 2015 ACR complete form (incorporating imaging and MSU data) for diagnosing gout were 88.13% and 95.38%, respectively. The area under the curves (AUC) of 2015 ACR "complete form (incorporating imaging and MSU data)", 2015 ACR "clinical form (incorporating clinical parameters)", 2010 Netherlands criteria and 1977 ARA criteria were 0.982, 0.983, 0.963, and 0.928, respectively. For the 94 early gout patients, the AUC of the above criteria were 0.973, 0.968, 0.916, and 0.910, respectively. For the established gout patients, the AUC were 0.987, 0.991, 0.982, and 0.936, respectively. For the patients with disease duration within two years, the odd ratio (OR) for sensitivity of 2015 ACR "complete form (incorporating imaging and MSU data)", 2015 ACR "clinical form (incorporating clinical parameters)", 2010 Netherlands criteria and 1977 ARA criteria were 1.562 (1.003-2.435), 1.500 (1.001-2.346), and 1.812 (1.177-2.791), nevertheless, for the patients with established gout, the OR were 1.702 (1.300-2.229), 1.607 (1.224-2.110), and 1.821 (1.396-2.377), respectively. CONCLUSION: The 2015 ACR/EULAR criteria are more accurate in gout diagnosis compared with the 1977 ARA criteria by elevating the sensitivity and specificity, in respective of the disease duration. The 2015 ACR/EULAR criteria may serve as new diagnostic tools in daily clinical practice in Chinese patients.


Subject(s)
Gout/diagnosis , Arthritis, Rheumatoid/complications , Asian People , Gout/complications , Gout/therapy , Humans , Rheumatology , Sensitivity and Specificity , Synovial Fluid , United States
16.
Zhonghua Yi Xue Za Zhi ; 97(45): 3524-3528, 2017 Dec 05.
Article in Chinese | MEDLINE | ID: mdl-29275588

ABSTRACT

Objective: To investigate the damage of gray matter structure in MRI-negative epilepsy patients with different symptoms by voxel-based morphometry (VBM). Methods: From June, 2009 to October, 2016, ninety MRI-negative epilepsy patients and thirty-five healthy volunteers underwent the 3T magnetic resonance imaging scan in Nanjing General Hospital. The patients were divided into three groups, including idiopathic generalized tonic-clonic seizure (I-GTCS), secondarily generalized tonic-clonic seizure (S-GTCS), and partial seizure (PS) according to different symptoms. The three-dimensional high-resolution T1 structural MRI data was obtained for the voxel-based morphometry. Data of gray matter structure from four groups were compared using one-way analysis of variance (ANOVA). An independent-sample t test was performed in order to compare gray matter volume of the three patient groups with controls respectively. According the results of ANOVA, impaired brain regions were selected as regions of interest in order to carry out correlation analysis between gray matter volume and disease duration. Results: ANOVA showed significant differences in gray matter structure of bilateral thalamus and frontal lobe between four groups (alphasim correction, P<0.01). Independent-sample t test showed that the volume of bilateral thalamus and frontal lobe decreased in all three patients groups (alphasim correction, P<0.01) .The volume of bilateral thalamus showed significantly negatively correlation with disease duration in I-GTCS patients (r=-0.466, P<0.01). Conclusions: Generalized seizures and partial seizures all can cause damage to the gray matter structure, especially in thalamus and frontal lobe. The impairments of thalamus and frontal lobe in patients with different seizure types are different with the progression of disease, which suggests that influences of different epilepsy seizures on the thalamo-cortical network are different.


Subject(s)
Epilepsy/diagnostic imaging , Gray Matter/pathology , Seizures/diagnostic imaging , Brain , Case-Control Studies , Epilepsy/complications , Humans , Magnetic Resonance Imaging , Seizures/complications
17.
Nano Lett ; 17(3): 1616-1622, 2017 03 08.
Article in English | MEDLINE | ID: mdl-28145719

ABSTRACT

MoTe2 is an exfoliable transition metal dichalcogenide (TMD) that crystallizes in three symmetries: the semiconducting trigonal-prismatic 2H- or α-phase, the semimetallic and monoclinic 1T'- or ß-phase, and the semimetallic orthorhombic γ-structure. The 2H-phase displays a band gap of ∼1 eV making it appealing for flexible and transparent optoelectronics. The γ-phase is predicted to possess unique topological properties that might lead to topologically protected nondissipative transport channels. Recently, it was argued that it is possible to locally induce phase-transformations in TMDs, through chemical doping, local heating, or electric-field to achieve ohmic contacts or to induce useful functionalities such as electronic phase-change memory elements. The combination of semiconducting and topological elements based upon the same compound might produce a new generation of high performance, low dissipation optoelectronic elements. Here, we show that it is possible to engineer the phases of MoTe2 through W substitution by unveiling the phase-diagram of the Mo1-xWxTe2 solid solution, which displays a semiconducting to semimetallic transition as a function of x. We find that a small critical W concentration xc ∼ 8% stabilizes the γ-phase at room temperature. This suggests that crystals with x close to xc might be particularly susceptible to phase transformations induced by an external perturbation, for example, an electric field. Photoemission spectroscopy, indicates that the γ-phase possesses a Fermi surface akin to that of WTe2.

18.
Genet Mol Res ; 13(2): 3310-8, 2014 Apr 29.
Article in English | MEDLINE | ID: mdl-24841663

ABSTRACT

Xeroderma pigmentosum group D (XPD) plays a key role in the repair of DNA and platinum resistance lesions. Cytidine deaminase (CDA) genes determine the velocity of gemcitabine catalysis. This study aimed to investigate the relationship between XPD and CDA genotypes and outcome in non-small lung cancer (NSCLC) patients. We used polymerase chain reaction-restriction fragment length polymorphism to evaluate genetic polymorphisms of XPD (Asp312Asn and Lys751Gln) and CDA (Lys27Gln and Ala70Thr) in 93 NSCLC patients treated with a cisplatin-gemcitabine regimen. There were no significant correlations between the XPD polymorphisms Asp312Asn and Lys751Gln with clinical benefits (P>0.05). Time to progression (TTP) did not differ between patients with wild type genotypes and those heterozygous for the single nucleotide polymorphism loci of XPD. However, a significant difference was observed in overall survival (OS) between XPD Asp312Asp and XPD Asp312Asn individuals (20.0 vs 12.4 months, P=0.04). Furthermore, the OS of patients with wild type genotypes was longer (20.5 months) than that of patients carrying the XPD 751Lys/Gln polymorphism (11.5 months). No significant differences in TTP or OS were observed in patients carrying different genotypes of CDA Lys27Gln, and no mutations were observed at the CDA Ala70Thr site. These results provide suggestive evidence of a favorable effect for the XPD 312Asp/Asp and XPD 751Lys/Lys genotypes with respect to overall survival rates in platinum-treated NSCLC patients. However, the CDA 27 polymorphism does not appear to affect the efficacy of gemcitabine.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Carcinoma, Non-Small-Cell Lung/genetics , Cytidine Deaminase/genetics , Xeroderma Pigmentosum Group D Protein/genetics , Asian People , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/pathology , Cisplatin/administration & dosage , Deoxycytidine/administration & dosage , Deoxycytidine/analogs & derivatives , Disease-Free Survival , Female , Humans , Male , Middle Aged , Polymorphism, Single Nucleotide , Prognosis , Gemcitabine
19.
Poult Sci ; 93(3): 527-34, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24604844

ABSTRACT

To investigate the role of apoptosis in duck viral hepatitis pathogenesis, 4- and 21-d-old ducks were inoculated with duck hepatitis A virus serotype 1 and killed at 2, 6, 12, 24, and 48 h postinfection. TdT-mediated dUTP nick-end labeling was used to detect apoptosis cells. Expression profiles of apoptosis-related genes including caspase-3, -8, -9, and Bcl-2 in spleen, bursa of Fabricius, liver, and the quantity of virus in blood were examined using real-time PCR. The TdT-mediated dUTP nick-end labeling analysis indicated there was a significant difference of apoptotic cells between treatments and controls. The same difference also appeared in virus amount variation in blood during infection. Gene expression analysis revealed that the apoptosis-related gene expression profile was different in the 2 groups, and also different between various organs. This study suggested that apoptosis may play an important role in duck hepatitis A virus serotype 1 infection, and apoptosis suppression might facilitate virus multiplication, resulting in the highest virus concentration in the host.


Subject(s)
Apoptosis , Ducks , Hepatitis Virus, Duck/physiology , Picornaviridae Infections/veterinary , Poultry Diseases/physiopathology , Animals , Bursa of Fabricius/physiology , Bursa of Fabricius/virology , Gene Expression Regulation , Hepatitis Virus, Duck/isolation & purification , In Situ Nick-End Labeling/veterinary , Liver/physiology , Liver/virology , Organ Specificity , Picornaviridae Infections/genetics , Picornaviridae Infections/physiopathology , Picornaviridae Infections/virology , Poultry Diseases/genetics , Poultry Diseases/virology , Real-Time Polymerase Chain Reaction/veterinary , Spleen/physiology , Spleen/virology , Virus Replication
20.
J Phys Condens Matter ; 23(13): 135305, 2011 Apr 06.
Article in English | MEDLINE | ID: mdl-21415478

ABSTRACT

In this article we examine the low-temperature specific heat of slow-cooled Cu(0.2)Ag(2.8)SbSeTe(2) and the thermoelectric performance of quenched samples. We find that the low-temperature specific heat is dominated by two Einstein terms of approximate energies of 2.5 and 5 meV. The specific-heat behavior is consistent with the amorphous low-temperature thermal conductivity behavior and validates the glassy nature of the structure. We performed the synthesis of quenched samples in an attempt to eliminate the presence of micro-cracks, whose existence presumably enhances electronic scattering. We find that quenching eliminates the presence of micro-cracks but does not result in an improvement of the figure of merit. Specifically, the highest ZT obtained in the quenched samples (ZT = 1.5), though very competitive, is still significantly less that the ZT obtained in the slow-cooled samples (ZT = 1.75).


Subject(s)
Alloys/chemistry , Copper/chemistry , Selenium/chemistry , Silver/chemistry , Tellurium/chemistry , Thermal Conductivity , Cold Temperature , Electric Conductivity , Electric Impedance , Electronics/methods , Hot Temperature , Microscopy, Electron, Transmission/methods , Models, Chemical , Temperature , Vibration
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