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1.
Phys Rev Lett ; 132(7): 072502, 2024 Feb 16.
Article in English | MEDLINE | ID: mdl-38427897

ABSTRACT

Using the fusion-evaporation reaction ^{106}Cd(^{58}Ni,4n)^{160}Os and the gas-filled recoil separator SHANS, two new isotopes _{76}^{160}Os and _{74}^{156}W have been identified. The α decay of ^{160}Os, measured with an α-particle energy of 7080(26) keV and a half-life of 201_{-37}^{+58} µs, is assigned to originate from the ground state. The daughter nucleus ^{156}W is a ß^{+} emitter with a half-life of 291_{-61}^{+86} ms. The newly measured α-decay data allow us to derive α-decay reduced widths (δ^{2}) for the N=84 isotones up to osmium (Z=76), which are found to decrease with increasing atomic number above Z=68. The reduction of δ^{2} is interpreted as evidence for the strengthening of the N=82 shell closure toward the proton drip line, supported by the increase of the neutron-shell gaps predicted in theoretical models.

2.
Zhonghua Gan Zang Bing Za Zhi ; 31(8): 842-846, 2023 Aug 20.
Article in Chinese | MEDLINE | ID: mdl-37723066

ABSTRACT

Objective: intrahepatic portocaval shunt (TIPS) in the treatment of hepatic sinusoidal obstruction syndrome (HSOS). Methods: A retrospective analysis was performed on 27 patients with HSOS who were treated with TIPS in our center from July 2018 to July 2020. The changes of portal vein pressure (PVP), portal vein pressure gradient (PPG) and liver function were observed, so as to evaluate the efficacy. Paired t test was adopted to evaluate the quantitative parameters, while χ (2) test was used to analyze qualitative parameters, with P < 0.05 as statistical difference. Results: PVP decreased from (4.41 ± 0.18) kPa before shunt to (2.69 ± 0.11) kPa after shunt (t = 82.41, P < 0.001), PPG decreased from (3.23 ± 0.18) kPa before shunt to (1.46 ± 0.23) kPa after shunt (t = 32.41, P < 0.001). The liver function improved significantly after operation. After 24 months of follow-up, 3 patients developed stent restenosis and recanalized after balloon dilation. Three patients developed hepatic encephalopathy, which was improved after drug treatment. One patient underwent liver transplantation due to liver failure. Conclusion: TIPS is effective in the treatment of HSOS in the short and medium term, and can provide time for liver transplantation patients to wait for liver source.


Subject(s)
Hepatic Encephalopathy , Hepatic Veno-Occlusive Disease , Liver Diseases , Humans , Retrospective Studies
3.
Zhonghua Yi Xue Za Zhi ; 103(9): 677-683, 2023 Mar 07.
Article in Chinese | MEDLINE | ID: mdl-36858368

ABSTRACT

Objective: To investigate the application of transcranial facial nerve motor evoked potential (FNMEP) and direct nerve electrical stimulation (DNES) for the prediction of facial nerve function after vestibular schwannoma surgery. Methods: The clinical data of 106 patients who underwent vestibular schwannoma surgery under electrophysiological monitoring of facial nerve between 2017 and 2021 were retrospectively examined, and there were 57 males and 49 females, with a mean age of (51±11) years. Neuroelectrophysiological monitoring was performed in all patients during the operation. After the tumor was removed, FNMEP and DNES were used for electrophysiological evaluation of facial nerve function. The amplitude ratios of FNMEP to baseline (M1) and the brainstem segment to the internal auditory canal segment of DNES (M2) were recorded after the tumor was removed, respectively. The correlation between these two ratios and facial nerve function at 1 day, 1 month and 3 months after the operation were compared. According to the House-Brackmann (HB) scale, Grade Ⅰ-Ⅱ refers to good facial nerve function, and grade Ⅲ-Ⅵ refers to moderate and severe facial nerve dysfunction. Non-parameter Spearman correlation coefficient was used to evaluate the correlation between M1 and M2 and facial nerve function at 1 day, 1 month and 3 months after operation, and the receiver operating characteristic (ROC) curves were plotted to verify the diagnostic efficacy of M1 and M2 for predicting the prognosis of postoperative facial nerve function. Results: Among 106 patients, 102 cases (96.3%) underwent total tumor resection, 4 patients (3.7%) underwent subtotal resection, 104 patients (98.1%) had anatomical preservation of facial nerves, and there were no deaths reported. All patients could evoke reliable FNMEP and 2 patients could not evoke DNES in the brainstem segment of the facial nerve. There were 81 (76.4%), 99 (93.4%) and 103 patients (97.2%) with satisfactory function of facial nerve at 1 day, 1 month and 3 months after surgery, respectively. M1 had large absolute values of Spearman correlation coefficient at 1 day (ρ=|-0.648|) and 1 month (ρ=|-0.552|) after surgery (both P<0.001), while M2 showed a greater absolute value of Spearman correlation coefficient at 3 months (ρ=|-0.395|) than that of M1 (ρ=|-0.378|) (P<0.001). Cut-off value of M1 was 0.58 (sensitivity=0.92, specificity=0.64), and that of M2 was 0.36 (sensitivity=0.64, specificity=1.00). Meanwhile, M1<0.58 or M2<0.36 suggested moderate and severe impairment of facial nerve function. Conclusions: Both FNMEP and DNES during vestibular schwannoma surgery can effectively evaluate the postoperative facial nerve function. FNMEP is better than DNES in predicting the early postoperative facial nerve function, but DNES is better for predicting the long-term postoperative facial nerve function.


Subject(s)
Neuroma, Acoustic , Female , Male , Humans , Adult , Middle Aged , Facial Nerve , Retrospective Studies , Brain Stem , Electric Stimulation
4.
Sci Rep ; 13(1): 3701, 2023 Mar 06.
Article in English | MEDLINE | ID: mdl-36879103

ABSTRACT

Hydraulic rotary drilling can offer the essential information and core samplesa for the researches on solid earth. Recording the factual field drilling data and analyzing the hydraulic rotary coring process are challenging yet promising to utilize the massive drilling information in geophysics and geology. This paper adopts the drilling process monitoring (DPM) technique and records the four parameters of displacement, thrust pressure, upward pressure, and rotation speed in real-time series for profiling the siliciclastic sedimentary rocks along 108 m deep drillhole. The digitalization results with 107 linear zones represent the spatial distribution of drilled geomaterials including superficial deposits (fill, loess, gravelly soil), mudstone, silty mudstone, gritstone, and fine sandstone. The constant drilling speeds varying from 0.018 to 1.905 m/min present the in-situ coring resistance of drilled geomaterials. Furthermore, the constant drilling speeds can identify the strength quality of soils to hard rocks. The thickness distributions of the six basic strength quality grades are presented for all the sedimentary rocks and each individual type of the seven soil and rocks. The in-situ strength profile determined in this paper can be used to assess and evaluate the in-situ mechanical behavior of geomaterial along the drillhole and can provide a new mechanical-based assessment for determining the spatial distribution of geological strata and structures in subsurface. They are important since the same stratum at different depths can have different mechanical behavior. The results provide a novel quantitative measurement for continuously in-situ mechanical profiling by digital drilling data. The findings of the paper can offer a new and effective method for refinement and upgrading of in-situ ground investigation, and can provide researchers and engineers with a novel tool and valuable reference to digitize and utilize factual data of current drilling projects.

5.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 58(3): 277-280, 2023 Feb 28.
Article in Chinese | MEDLINE | ID: mdl-36854430
6.
Zhonghua Yan Ke Za Zhi ; 58(9): 706-708, 2022 Sep 11.
Article in Chinese | MEDLINE | ID: mdl-36069092

ABSTRACT

A 19-year-old patient with bilateral eyelid swelling for more than 2 years visited the Department of Ophthalmology. Physical examination disclosed a moderately active mass in the upper eyelid and lacrimal gland area in each eye. Orbital MRI showed that the lacrimal glands were significantly enlarged and moved forward in both eyes, and the enlargement was more severe in the left eye. The patient was admitted twice to the hospital for removal of orbital masses and was diagnosed as orbital Rosai-Dorfman disease by histopathological examination. During three months of follow-up, the patient was in good physical condition, and there was no tumor recurrence.


Subject(s)
Histiocytosis, Sinus , Lacrimal Apparatus , Orbital Diseases , Adult , Eyelids , Histiocytosis, Sinus/diagnosis , Histiocytosis, Sinus/pathology , Humans , Hypertrophy , Lacrimal Apparatus/pathology , Orbital Diseases/diagnosis , Tomography, X-Ray Computed , Young Adult
7.
Zhonghua Gan Zang Bing Za Zhi ; 30(7): 722-727, 2022 Jul 20.
Article in Chinese | MEDLINE | ID: mdl-36038341

ABSTRACT

Objective: To explore the correlation between portal vein pressure gradient (PPG) and hepatic vein pressure gradient (HVPG) in patients with portal hypertension (PHT). Methods: 752 cases with portal hypertension (PHT) who underwent transjugular intrahepatic portosystemic shunt (TIPS) and met the enrollment criteria between January 2016 to December 2019 were analyzed for hepatic vein, inferior vena cava and portal vein pressure. Paired t-test was used for analysis. Pearson correlation test was used to estimate correlation coefficient and coefficient of determination. P<0.05 were considered statistically significant. Results: Wedged hepatic vein pressure (WHVP), portal vein pressure (PVP), correlation coefficient, and coefficient of determination were 27.98±8.95 mmHg, 33.85±7.33 mmHg, 0.329 (P<0.001), and 0.108, respectively. HVPG, PPG,correlation coefficient, and coefficient of determination were 16.84±7.97 mmHg, 25.11±6.95 mmHg (P<0.001), 0.145, and 0.021 (P<0.001), respectively. The difference between HVPG and PPG was greater than 5 mmHg in 524 cases, accounting for 69.7%. The difference between HVPG and PPG was within 5 mmHg or basically equal in 228 cases, accounting for 30.3%. The correlation coefficient between free hepatic venous pressure (FHVP) and inferior vena cava pressure (IVCP) was 0.568 (P<0.001), and the coefficient of determination was 0.323. According to the presence or absence of hepatic venous collaterals after balloon occluded hepatic angiography, they were divided into two groups: 157 (20.9%) cases in the group with hepatic venous collaterals, and 595 (79.1%) cases in the group without hepatic venous collaterals. The parameters of the two groups were compared: WHVP (15.73±3.63) mmHg vs. (31.22±6.90) mmHg, P<0.001; PVP (31.69±8.70) mmHg vs. (34.42±6.81) mmHg, P<0.001; HVPG (7.18±4.40) mmHg vs. (19.40±6.62) mmHg, P<0.001; PPG (24.24±8.11) mmHg vs. (25.34±6.60) mmHg, P<0.001; free hepatic venous pressure (FHVP) (8.58±3.37) mmHg vs. (11.82±5.07) mmHg , P<0.001; inferior vena cava pressure (IVCP) (7.45±3.29) mmHg vs. (9.09±4.14) mmHg, P<0.001. Conclusion: The overall correlation is poor between HVPG and PPG. HVPG of most patients is not an accurate representation of PPG, and the former is lower than the latter. Hepatic venous collateral formation is one of the important reasons for the serious underestimation of HVPG values.


Subject(s)
Hypertension, Portal , Portasystemic Shunt, Transjugular Intrahepatic , Hepatic Veins , Humans , Liver Cirrhosis , Portal Pressure , Vena Cava, Inferior
8.
Zhonghua Bing Li Xue Za Zhi ; 51(4): 314-318, 2022 Apr 08.
Article in Chinese | MEDLINE | ID: mdl-35359042

ABSTRACT

Objective: To investigate the clinicopathological features and treatment strategies of pituicytoma. Methods: Twenty-one cases of pituicytoma were collected at the First Affiliated Hospital of Nanjing Medical University and Jinling Hospital, Nanjing, China from 2009 to 2020. The clinical data of 21 pituicytoma patients was retrospectively analyzed, and the relevant literature was reviewed. Results: Twenty-one patients aged 4 to 68 years, including 8 males and 13 females. All patients underwent surgical treatment. Histologically, the tumor was consisted almost entirely of elongate, bipolar spindle cells arranged in a fascicular or storiform pattern. Mitotic figures were rare. Immunohistochemically, tumor cells were diffusely positive for S-100 protein (21/21), vimentin (15/15) and TTF1 (14/14), while they were weakly or focally positive for GFAP (13/16) and EMA (6/12). CKpan was negative in all cases and Ki-67 proliferation index was low (<5%). Among the 18 patients with follow-up, all survived and 2 relapsed after surgery. Conclusions: Pituicytoma is a rare low-grade glioma of the sellar area. It is easily confused with other sellar tumors. Preoperative diagnosis is difficult. It needs to be confirmed by histopathology and immunohistochemistry. Microsurgery is the main treatment method at present.


Subject(s)
Craniopharyngioma , Glioma , Pituitary Neoplasms , Adolescent , Adult , Aged , Child , Child, Preschool , Female , Glioma/pathology , Humans , Immunohistochemistry , Male , Middle Aged , Pituitary Neoplasms/pathology , Retrospective Studies , Young Adult
9.
Zhonghua Gan Zang Bing Za Zhi ; 30(2): 220-223, 2022 Feb 20.
Article in Chinese | MEDLINE | ID: mdl-35359075

ABSTRACT

Objective: To investigate the practicability and safety of transjugular liver biopsy (TJLB). Methods: Data of 53 cases with transjugular liver biopsy from June 2015 to June 2020 were collected. LABS-100 was used in all patients who underwent transjugular liver biopsy. Among them, 45 cases and eight were biopsied via hepatic vein and intrahepatic segment of the inferior vena cava. The surgical indications, related complications, and postoperative pathological diagnosis were analyzed and summarized. Results: TJLB was successful in all patients, with an average of 2.8 punctures per case. Satisfactory liver tissue and histopathological diagnosis was obtained in all patients. Two cases developed a cervical hematoma that was improved spontaneously, and one patient developed an intrahepatic hematoma that was improved after conservative treatment. Conclusion: TJLB is a practical and safe method for patients with contraindications to percutaneous liver biopsy.


Subject(s)
Jugular Veins , Liver Diseases , Biopsy/adverse effects , Biopsy/methods , Biopsy, Needle/methods , Humans , Liver Diseases/pathology
10.
J Phys Condens Matter ; 34(16)2022 Feb 21.
Article in English | MEDLINE | ID: mdl-35105834

ABSTRACT

Schottky junctions, formed by high work function metals and semiconductors, are important devices in electronics and optoelectronics. The metal deposition in traditional Schottky interfaces usually damages the semiconductor surface and causes defect states, which reduces the Schottky barrier height and device performance. This can be avoided in the atomically smooth interface formed by two-dimensional (2D) metals and semiconductors. For better interface tailoring engineering, it is particularly important to understand various interface effects in such 2D Schottky devices under critical or boundary conditions. Here we report the fabrication and testing of three types of MoS2devices, i.e., using PtTe2, Cr and Au as contact materials. While the Cr/MoS2contact is an ohmic contact, the other two are Schottky contacts. The van-der-Waals interface of PtTe2-MoS2results in a well-defined OFF state and a significant rectification ratio of 104. This parameter, together with an ideality factor 2.1, outperforms the device based on evaporated Au. Moreover, a device in the intermediate condition is also presented. An abrupt increase in the reverse current is observed and understood based on the enhanced tunneling current. Our work manifests the essential role of doping concentration and provides another example for 2D Schottky interface design.

11.
J Phys Condens Matter ; 33(39)2021 Jul 27.
Article in English | MEDLINE | ID: mdl-34252886

ABSTRACT

Two-dimensional (2D) materials attached with flexible substrates enable possibilities to apply their superior properties to the rapidly increasing demand for foldable displays and wearable biosensors in the internet-of-things technology. However, previous two-step strategy to construct the flexible devices, namely first obtaining 2D materials elsewhere and then transferring them onto flexible substrates, can cause huge problems, including irreversibly undermining the device performance and limiting the material size. Here we propose a new one-step strategy (other than the liquid phase processing and low temperature synthesis methods), namely directly depositing appropriate 2D materials onto flexible substrates, which involves no transferring and can maintain the crystal quality and properties to the greatest extent. More importantly, this strategy in principle has no limit in the film size, hence removing a main obstacle for the practical use of flexible films, such as complex logic operations and large-area optoelectronic applications. Using this strategy, a centimeter-scale SnSe2film is directly grown on polydimethylsiloxane, which is characterized as a uniform, out-of-plane oriented and semiconducting film that is robust to deformations. Based on the film, a flexible photodetector is fabricated and distinct photoresponse to a broad spectrum of light (405-830 nm) is observed, with remarkable technical parameters.

12.
Ann R Coll Surg Engl ; 103(6): 438-443, 2021 Jun.
Article in English | MEDLINE | ID: mdl-33852371

ABSTRACT

INTRODUCTION: Lingual thyroglossal duct cysts (LTGDC) are a rare kind of thyroglossal duct cyst. However, Sistrunk surgery is not very suitable for this type of cyst. This study aimed to explore the efficacy of transoral excision of LTGDC by plasma coblation. METHODS: The present study reviewed 11 patients, comprising seven males and four females, who had been diagnosed with LTGDC preoperatively by computed tomography (CT) and fibre-optic electronic laryngoscopy. Of those patients, two had recurrence after surgery of epiglottic cysts. All these patients underwent transoral excision by plasma coblation. Then, we collected preoperative data of the patients, observed the effect of surgery, and analysed factors relevant to LTGDC, including the estimated bleeding amount, postoperative hospitalisation, complications and recurrence rates. RESULTS: The connection between LTGDC and hyoid was tapered on sagittal images of CT, which was vital evidence for the diagnosis of LTGDC. Surgery was performed successfully for all 11 patients, and all recovered without complication. There was no evidence of recurrence after surgery, during follow up for 3-43 months. CONCLUSIONS: Transoral surgery for LTGDC can be performed successfully by plasma coblation, which is an effective and safe surgical treatment. Fibre-optic electronic laryngoscopy and CT are essential to the diagnosis of LTGDC in order to avoid missing detection and misdiagnosis.


Subject(s)
Electrosurgery/methods , Thyroglossal Cyst/surgery , Adolescent , Adult , Blood Loss, Surgical , Electrosurgery/adverse effects , Female , Humans , Laryngoscopy/methods , Length of Stay , Male , Middle Aged , Mouth , Recurrence , Thyroglossal Cyst/diagnostic imaging
15.
Biochemistry (Mosc) ; 85(3): 334-343, 2020 Mar.
Article in English | MEDLINE | ID: mdl-32564738

ABSTRACT

Obesity and latent inflammation can give rise to insulin resistance and type 2 diabetes. Here we established an insulin resistance model of osteoblasts to explore the restoration effect of anti-inflammatory interleukin-4 (IL-4) on insulin sensitivity and its mechanism. We found that IL-4 inhibited cell proliferation in a concentration- and time-dependent manner. Insulation resistance significantly reduced the phosphorylation levels of the insulin receptor substrate 1 (IRS1; Tyr612), Akt (Ser473), and AS160 (Ser318) proteins. The addition of IL-4 to the insulin resistance model led to a dose-dependent stimulation of the phosphorylation of IRS1, Akt, and AS160. IL-4 fully restored the activation of the insulin cascade in insulin-resistant cells at the concentration of 50 ng/ml. Additionally, IL-4 promoted the expression of IRS1 in a time-dependent manner. We conjecture that IL-4 restores insulin sensitivity in osteoblasts by upregulating the expression of IRS1. It was also found that IL-4 promoted the expression of osteoprotegerin depending on the time of exposure. This effect may play an important role in the regulation of the energy metabolism in the whole body.


Subject(s)
Gene Expression Regulation , Insulin Receptor Substrate Proteins/metabolism , Insulin Resistance , Insulin/metabolism , Interleukin-4/metabolism , Osteoblasts/metabolism , Cell Differentiation , Cell Line, Tumor , Cell Proliferation , Cell Survival , Energy Metabolism , Humans , Inflammation , Lipids/chemistry , Obesity/metabolism , Osteoprotegerin/metabolism , Phosphorylation
16.
Article in Chinese | MEDLINE | ID: mdl-32185924

ABSTRACT

OBJECTIVE: To investigate the distribution and identify the genetic genetics of invasive Pomacea species in Xihu District, Hangzhou City, so as to understand the spread tendency of Pomacea species. METHODS: The specimens of Pomacea species were collected from five sites in water systems (lakes, rivers and wetlands) and its costal lands in Xihu District, Hangzhou City in 2017 for morphological identification. Total DNA was isolated from the foot tissues of adult snails for amplification of the COI gene, and haplotype diversity and nucleic acid diversity analyses were performed. In addition, a phylogenetic tree was created based on the haplotype captured from GenBank and those from this study to investigate the phylogenetic relationships. RESULTS: Pomacea specimens, which were preliminarily characterized as Pomacea, were found in ponds, rivers and wetlands in Xihu District of Hangzhou City. A total of 16 sequences were captured from the DNA samples of Pomacea specimens, which belonged to 3 haplotypes, including Hap1, Hap2 and Hap3. A high frequency was seen in Hap1 and Hap3, and a low frequency was found in Hap2. The Pomacea specimens collected from the 5 sites in Xihu Districts included P. canaliculata and P. maculate. The Pomacea specimens with a Hap1 had a close genetic relationship with the P. canaliculata from Argentina, Guangdong Province and Hong Kong Special Administrative Region of China, and the Pomacea specimens with a Hap2 had a close genetic relationship with the P. canaliculata from Argentina, Japan and Guangzhou City of Guangdong Province, China, while the Pomacea specimens with a Hap2 had a close genetic relationship with the P. maculate from Argentina and Brazil. CONCLUSIONS: P. canaliculata and P. maculata are present in Xihu District of Hangzhou City. P. maculata may spread to Xihu District through multiple introductions or water flow.


Subject(s)
Genetics, Population , Introduced Species , Snails , Animals , China , Haplotypes , Phylogeny , Snails/classification , Snails/genetics
17.
Beijing Da Xue Xue Bao Yi Xue Ban ; 52(1): 64-70, 2020 Feb 18.
Article in Chinese | MEDLINE | ID: mdl-32071465

ABSTRACT

OBJECTIVE: To compare the clinical effects of ultrasonic subgingival debridement and ultrasonic subgingival debridement combined with manual root planing on severe periodontitis and then to investigate the necessity and significance of manual root planing. METHODS: Twenty-three patients with severe periodontitis participated in this split-mouth randomized-controlled clinical trial. Baseline examination and randomization were performed after supragingival scaling: each of the upper and lower jaws had a quadrant as the test group treated with ultrasonic subgingival debridement combined with manual root planing, whereas the other two quadrants were the control group treated with ultrasonic subgingival debridement. Treatment of each patient was at intervals of one week and completed in two visits. Clinical indicators concerning probing depth (PD), clinical attachment loss (CAL) and bleeding index (BI) were recorded at baseline and 1 month, 3 months, 6 months after treatment. RESULTS: There was no significant difference of periodontal indicators between the test group and the control group at baseline. Both the test group and control group resulted in significant improvement of PD, CAL and BI. One and three months after treatment, reduction of PD in the test group was higher than that in the control group [1 month: (2.13±1.31) mm vs. (1.79±1.33) mm, P<0.01; 3 months: (2.46±1.33) mm vs. (2.17±1.38) mm, P<0.01] and reduction of CAL in the test group was higher than that in the control group [1 month: (1.89±2.03) mm vs. (1.65±1.93) mm, P<0.01; 3 months: (2.03±2.05) mm vs. (1.83±1.97) mm, P<0.05]. Six months after treatment, PD in the test group and the control group decreased by (2.52±1.40) mm and (2.35±1.37) mm respectively, and the improvement in the test group was significantly better than that in the control group (P<0.01). CAL in the test group and the control group decreased by (1.89±2.14) mm and (1.77±2.00) mm respectively, and there was no statistical difference between the groups. There was no significant difference in the changes of BI between the two groups 1, 3 and 6 months after treatment. CONCLUSION: Ultrasonic subgingival debridement combined with manual root planing has more reduction in PD and CAL compared with ultrasonic subgingival debridement. Therefore, it is still necessary to use manual instruments for root planing following ultrasonic subgingival debridement.


Subject(s)
Periodontitis , Ultrasonics , Debridement , Dental Scaling , Humans , Root Planing , Treatment Outcome
18.
Beijing Da Xue Xue Bao Yi Xue Ban ; 53(1): 69-75, 2020 Dec 28.
Article in Chinese | MEDLINE | ID: mdl-33550338

ABSTRACT

OBJECTIVE: To compare the residual cement between computer aided design/computer aided manufacturing customized abutments (CCA) and stock abutments (SA), and to evaluate the feasibility of digital measurement for residual cement volume by three-dimensional scanning. METHODS: Twenty master models needed in this study were all taken from one 47-year-old patient with arrested periodontitis, who had already had an implant placed at his right upper central incisor site in the Department of Periodonto-logy, Peking University School and Hospital of Stomatology. After 4 weeks of soft tissue conditioning by means of customized healing abutment, the height of peri-implant soft tissue was measured, from the implant platform to mucosal margin, as 5 mm. Using customized impression coping, the impression was taken and twenty models were fabricated and allocated to 4 groups according to the type of abutments: CCA1 (5 mm transmucosal height CCA, with margin at tissue level), CCA2 (4 mm transmucosal height CCA, with 1 mm submucosal margin), SA1 (3 mm transmucosal height SA, with 2 mm submucosal margin) and SA2 (1 mm transmucosal height SA, with 4 mm submucosal margin). Crowns were cemented to the abutments, which were seated on the working models. Excess cement was removed by a prosthodontic specialist. Thereafter, the volume of residual cement was evaluated by using three-dimensional scanning technique. The area proportion of residual cement was calculated on photographs taken by a single lens reflex camera. The weight of residual cement was weighed by an analytical balance. And the correlation of residual cement volume data with residual cement area proportion or weight of residual cement acquired by traditional methods was analyzed. RESULTS: Residual cement was observed on all the experiment samples. The residual cement volume of CCA was significantly less than that of SA [(0.635 3±0.535 4) mm3 vs. (2.293 8±0.943 8) mm3, P < 0.001]. Consistently, CCA had less residual cement area proportion and weight than those of SA [area proportion: 7.57%±2.99% vs. 22.68%±10.06%, P < 0.001; weight: (0.001 5±0.001 0) g vs. (0.003 7±0.001 4) g, P < 0.001]. The residual cement volume was strongly correlated with the residual cement area proportion and residual cement weight (r>0.75, P < 0.001). CONCLUSION: These in vitro results suggest that CCA minimized the residual cement more effectively than SA. The method to digitally evaluate the residual cement volume is feasible, but its validity and reliability need to be further studied.


Subject(s)
Computer-Aided Design , Crowns , Aged, 80 and over , Bone Cements , Dental Abutments , Dental Prosthesis, Implant-Supported , Glass Ionomer Cements , Humans , Reproducibility of Results
19.
Beijing Da Xue Xue Bao Yi Xue Ban ; 51(6): 1130-1137, 2019 Dec 18.
Article in Chinese | MEDLINE | ID: mdl-31848517

ABSTRACT

OBJECTIVE: To explore the effects from the thread shapes of custom-made root-analogue implant (RAI) on distributions of von Mises stress around the peri-implant bone. METHODS: Five one-stage RAI three-dimensional finite element (FE) models with different thread shapes (V-shaped design, square design, buttress design, reverse buttress design and none thread design) and congruent bone were created through reverse engineering technology. The data of the five models were imported into the FE analysis software to calculate. A force of 100 N was applied parallelly and of 45° to the implant axis respectively. Analysis was performed to evaluate the von Mises stress distributions at the peri-implant regions with the help of the Ansys 16 software. RESULTS: The von Mises stresses distributed mostly at the implant cervical regions and the tip ends of the threads on the cortical bone under oblique loading, while on the cancellous bone, the stresses concentrated mostly on the implant lateral cervical regions, the tip ends of the threads and the apical regions. When under vertical loading, the von Mises stresses distributed mostly at the implant cervical regions on the cortical bone while at the tip ends of the threads and the lateral apical regions on the cancellous bone. The von Mises stresses were better distributed on the thread groups under both kinds of loadings compared with no thread design. But there was no obvious difference among the different thread groups. The concentrations of the von Mises stresses on the cancellous bone in the thread groups were mostly at the tip ends of the threads while less in the apical area. The von Mises stresses were better distributed on the cancellous bone on the other three thread designs than on square design. CONCLUSION: Thread designs are advocated for the reason that adding thread designs to the RAI standard design will have a positive effect on stress distributions at the peri-implant regions and it will reduce the concentrations of von Mises stresses on the cortical bone. From the standpoint of the stress distribution, V-shaped design, buttress design and reverse buttress design are more suitable for RAI than square design. There is no difference of the distributions of the von Mises stresses in the RAI between different thread designs.


Subject(s)
Dental Implants , Dental Prosthesis Design , Biomechanical Phenomena , Computer Simulation , Dental Stress Analysis , Finite Element Analysis , Software , Stress, Mechanical
20.
Article in Chinese | MEDLINE | ID: mdl-31446739

ABSTRACT

SummaryRenal clear cell carcinoma(RCCC) is the most common type of renal cell carcinoma, but metastasis to the nasal cavity is extremely rare. A case of RCCC to the nasal cavity and paranasal sinuses was reported. The early clinical manifestations of this case were intermittent epistaxis and subsequent massive epistaxis. Imaging examination revealed that there were masses in the nasal cavity and paranasal sinus, accompanied by bleeding and destruction of the skull base. Renal CT examination showed a tumor in the right kidney, and considered the patient suffering from renal cell carcinoma. The patient underwent a nasal side incision to remove the tumor, the patient's pathological return; nasal nephrogenic clear-cell carcinoma.


Subject(s)
Adenocarcinoma, Clear Cell/complications , Carcinoma, Renal Cell/complications , Kidney Neoplasms/complications , Nasal Cavity/pathology , Paranasal Sinus Neoplasms/secondary , Adenocarcinoma, Clear Cell/diagnosis , Humans , Paranasal Sinuses/pathology
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