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1.
Zhonghua Yi Xue Za Zhi ; 102(7): 506-512, 2022 Feb 22.
Artigo em Chinês | MEDLINE | ID: mdl-35184504

RESUMO

Objective: To establish the morphological reference values for the differential count of white blood cells in peripheral blood smear as well as nucleated cells and megakaryocytes in bone marrow smear. Methods: From April 2012 to June 2020, 4 221 healthy donors for hematopoietic stem cell transplantation in Hebei Yanda Lu Daopei Hospital were selected. The median age was 36 (3-72) years old, including 2 520 males and 1 701 females. They were divided into four groups according to age: children group, with age≤14 years old [n=334, 11 (3-14) years old], youth group, with age >14 years old and <45 years old [n=2 855, 33 (15-44) years old], middle-aged adult group, with age ≥45 years old and < 60 years old [n=929, 49 (45-59) years old], and older adult group, with age ≥60 years old [n=103, 62 (60-72) years old]. Gender subgroups were established in each age group. According to different hematopoietic characteristics, the children group were divided into two subgroups: children group 1 [n=48, 6 (3-7) years old] and children group 2 [n=286, 11 (8-14) years old]. According to the clinical routine, 100 white blood cells in peripheral blood, 200 nucleated cells in bone marrow, and cell numbers/4.5 cm2 for megakaryocytes were classified and counted. The results of cell count in different age and gender groups were compared, and the reference values of morphological classification were established for different groups with statistical or clinical significance. Results: Due to the existence of statistically significant differences between children and adult groups and different gender subgroups in adults (all P<0.05), the reference values were established for children group and adult gender subgroups. The counts of segmented neutrophils and lymphocytes in peripheral blood were 46.65(43.97-49.32)% and 44.00(10.60-65.10)% in children group 1, 50.73(49.50-51.96)% and 39.55 (38.36-40.74)% in children group 2, and 57.00 (39.00-75.23) % and 33.00 (17.00-52.00) % in adult group, respectively. Bone marrow segmented neutrophils, orthochromatic erythroblasts, and mature lymphocytes were 11.54 (10.68-12.41)%, 14.20 (13.19-15.21)%, and 23.99 (22.06-25.92)% in children group 1, 12.50 (7.00-21.50)%, 15.00(9.50-25.50)%, and 21.02 (20.24-21.81)% in children group 2, 13.50 (7.50-21.00)%, 16.50 (10.50-26.00)%, and 15.50 (7.50-26.00)% in adult male group, and 14.50 (8.00-24.50)%, 14.50 (9.00-23.00)%, and 17.50 (8.50-29.00)% in adult female group, respectively. The myelopoiesis/erythropoiesis ratio in children group, adult male group and adult female group was 1.86∶1 (1.14∶1-3.23∶1), 1.96∶1 (1.12∶1-3.19∶1), 2.22∶1 (1.30∶1-3.69∶1), respectively. The numbers of granular megakaryocytes and thromocytogenic megakaryocytes were 138 (25-567) cells/4.5cm2 and 86 (13-328) cells/4.5 cm2 in children group, and 92 (13-338) cells/4.5 cm2 and 38 (3-162) cells/4.5 cm2 in adult group, respectively. Conclusion: The morphological reference values for the differential count of white blood cells in peripheral blood smear as well as nucleated cells and megakaryocytes in bone marrow smear are successfully established, which is helpful to improve the application of morphological examination in disease screening, diagnosis and monitoring.


Assuntos
Medula Óssea , Megacariócitos , Animais , Células da Medula Óssea , Feminino , Contagem de Leucócitos , Leucócitos , Masculino , Valores de Referência
2.
Zhonghua Xue Ye Xue Za Zhi ; 42(2): 129-134, 2021 Feb 14.
Artigo em Chinês | MEDLINE | ID: mdl-33858043

RESUMO

Objective: To report the clinical manifestations and total exon detection results of one case of MYSM1 gene complex heterozygosity mutation of bone marrow failure syndrome 4 and the results of total exon detection of her family to provide a case phenotype for the early diagnosis of bone marrow failure syndrome 4. Methods: A 1-month-old girl with severe anemia was sequenced with trio-WES. Similarly, the family was also sequenced with tribe-WES to confirm the molecular diagnosis. BWA, GATK, and other software were used for annotation analysis of sequencing results. After polymerase chain reaction, Sanger sequencing was performed by ABI3730 sequencer to verify the target sequence. Moreover, the verification results were obtained by the sequence analysis software. The clinical diagnosis of this girl was reported and the relevant pieces of literature were reviewed. Results: The girl presented with pancytopenia, polydactylism, nonspecific white matter changes, and cysts. However, CD3(-)CD19(+) B decreased. The child was identified with MYSM1 complex heterozygous mutation by whole-exome sequencing, NM_001085487.2:c.1607_c.1611delAAGAG and c.1432C>T, which was respectively inherited from his parents. Genealogy verification confirmed that the c.1432C>T mutation carried by the father was from the grandfather (father's father) , whereas the c.1607_c.1611delAAGAG mutation carried by the mother was from the grandfather (mother's father) , whereas the grandmothers, aunts, and uncle did not carry the mutation. The child was diagnosed with BMFS4 combined with clinical phenotypic and molecular genetic findings. Conclusion: This case provides a case phenotype for the early diagnosis of BMFS4 and extends the pathogenicity variation and phenotype spectrum of the MYSM1 gene. The newly discovered pathogenic variant of MYSM1 c. 1607_c.1611delAAGAG has not been reported at home or abroad.


Assuntos
Transativadores , Proteases Específicas de Ubiquitina , Transtornos da Insuficiência da Medula Óssea , Criança , Feminino , Heterozigoto , Humanos , Lactente , Mutação , Linhagem , Sequenciamento do Exoma
3.
Zhonghua Zhong Liu Za Zhi ; 43(2): 207-212, 2021 Feb 23.
Artigo em Chinês | MEDLINE | ID: mdl-33601486

RESUMO

Objective: To explore the diagnostic accuracy improved by magnetic resonance imaging (MRI) biomarkers for lymph node metastasis in T1-2 stage rectal cancer before treatment. Methods: Medical records of 327 patients with T1-2 rectal cancer who underwent pretreatment MRI and rectal tumor resection between January 2015 and November 2019 were retrospectively analyzed. Fifty-seven cases were divided into the lymph node metastasis group (N+ group) while other 270 cases in the non-lymph node metastasis group (N-group) according to the pathologic diagnosis. Two radiologist evaluated the tumor characteristics of MRI images. The relationship of the clinical and imaging characteristics of lymph node metastasis was assessed by using univariate analysis and multivariable logistic regression analysis. Receiver operating characteristic (ROC) curve was used to evaluate the diagnostic abilities for the differentiation of N- from N+ tumors. Results: Among the 327 patients, MR-N evaluation was positive in 67 cases, which was statistically different from the pathological diagnosis (P<0.001). The sensitivity, specificity and accuracy of MRI for lymph node metastasis were 45.6%, 84.8% and 78.0%, respectively. Multivariate regression analysis showed that tumor morphology (P=0.002), including mucus or not (P<0.001), and MR-N evaluation (P<0.001) were independent influencing factors for stage T1-2 rectal cancer with lymph node metastasis. The area under the ROC curve of rectal cancer with lymph node metastasis analyzed by the logistic regression model was 0.786 (95%CI: 0.720~0.852). Conclusions: Tumor morphology, including mucus or not, and MR-N evaluation can serve as independent biomarkers for differentiation of N- and N+ tumors. The model combined with these biomarkers facilitates to improve the diagnostic accuracy of lymph node metastasis in T1-2 rectal cancers by using MRI.


Assuntos
Neoplasias Retais , Humanos , Linfonodos/diagnóstico por imagem , Linfonodos/patologia , Metástase Linfática/diagnóstico por imagem , Imageamento por Ressonância Magnética , Estadiamento de Neoplasias , Neoplasias Retais/diagnóstico por imagem , Neoplasias Retais/patologia , Neoplasias Retais/cirurgia , Estudos Retrospectivos
4.
J Biol Regul Homeost Agents ; 34(2): 421-433, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32515177

RESUMO

Naringenin is a flavonoid compound with antioxidant effects. It is used to treat oxidative stress-related diseases, but its mechanism is unclear. In this experiment, we explored whether naringenin can increase the expression of superoxide dismutase 1(SOD1), reduce the oxidative stress of PC12 cells induced by homocysteine (Hcy), and decrease the apoptosis of PC12 cells induced by Hcy by inhibiting the expression of mir-224-3p. Different concentrations of Hcy (1, 3, 5, 8, and 10 mmol/L) was used to analyze effect of homocysteine on PC12 cells. A total of 5 mmol/L Hcy was used to induce the excitatory and neurotoxicity model of PC12 cells in vitro. The cells were divided into normal control, Hcy induction, Hcy + Naringenin (25 µM), Hcy + Naringenin (50 µM), Hcy + Naringenin (75 µM), Hcy + Naringenin (100 µM), and Hcy + Naringenin (150 µM) groups. The relative survival rate and activities of the PC12 cells were determined by the MTT method, and the apoptosis rate of the PC12 cells was determined by using flow cytometry. The Western blot method was used to determine the expressions of SOD1, Bax, Caspase-3, Caspase-8, and Bcl-2 in the PC12 cells induced by Hcy. The expressions of SOD1 mRNA and miR-224-3p in the Hcy-induced PC12 cells were determined by RT-PCR. Results found that Hcy increased the expression of miR-224-3p in a dose-dependent manner but decreased that of SOD1 mRNA and protein. Hcy also increased oxidative stress in the PC12 cells and the proapoptotic proteins Bax, Caspase-3, and Caspase-9. Furthermore, it decreased the expression of anti-apoptotic protein Bcl-2 and the activity and survival rate of the HT22 cells, but it increased the apoptosis of the PC12 cells. The treatment of Hcy-induced PC12 cells with different concentrations of naringenin for 24 h decreased the expression of miR-224-3p in a dose-dependent manner and increased the expressions of SOD1 mRNA and protein. The treatment also decreased the oxidative stress in the PC12 cells and the expressions of pro-apoptotic proteins Bax, Caspase-3, and Caspase-9; increased the expression of anti-apoptotic protein Bcl- 2; decreased the apoptosis of the PC12 cells; and increased the PC12 cells.The results suggest that Naringenin can decrease the apoptosis and oxidative stress of PC12 cells induced by Hcy and increase the activities and survival rates of PC12 cells. The mechanism may be related to naringenin decreasing the expression of miR-224-3p in PC12 cells induced by Hcy and increasing the expressions of SOD1 mRNA and protein.


Assuntos
Flavanonas/farmacologia , MicroRNAs/genética , Neuroproteção , Superóxido Dismutase-1/genética , Animais , Apoptose , Caspase 3 , Caspase 9 , Homocisteína , Estresse Oxidativo , Células PC12 , Ratos , Regulação para Cima , Proteína X Associada a bcl-2
5.
Zhonghua Yi Xue Za Zhi ; 100(23): 1805-1811, 2020 Jun 16.
Artigo em Chinês | MEDLINE | ID: mdl-32536127

RESUMO

Objective: To analyze the cell morphological features of hepatosplenic T-cell lymphoma (HSTCL) gamma-delta (γδ) type, differentiate from acute leukaemia (AL). Methods: This was a retrospective study. The clinical data of four cases of HSTCL γδ type who were treated in Hebei Yanda Ludaopei Hospital from 2009 to 2014 were collected. Their initial morphology diagnoses in other hospitals were all acute leukemia or myelodysplastic syndrome (MDS). Morphological analysis and cytochemical stains to their bone marrow (BM) aspiration and peripheral blood (PB) smears were completed when they had no response to previous chemotherapies, and the morphological reports were compared with results of immunophenotyping, chromosome, and T cell receptor (TCR) gene rearrangement. Results: The percentages of malignant cells in four patients' BM aspirations were 7.6%-40.0%, and in two patients' PB was 9% and 10%, respectively. The morphology of four cases had a very high similarity in Wright's stain. Predominantly medium-sized cells were seen, with rich cytoplasm and frequently one big conspicuous nucleolus. The malignant cells resembled blasts, especially monoblasts, but with coarse granular chromatin, more compact than that in monoblasts. When comparing to malignant myeloblast and lymphoblasts, HSTCL cells were larger and more irregular in cell shape, with more abundant cytoplasm and prominent nuclear irregularity. The cytochemistric stain played an important role in differential diagnosis. HSTCL malignant cells showed non-specific esterase (NSE) negative or focal punctate activity which couldn't be inhibited by sodium fluoride. Periodic acid-Schiff (PAS) stain was negative or positive with a form of coarse granules. The myeloperioxdase (MPO) stain was negative. Conclusion: Malignant cells of HSTCL γδ type have very distinct morphological features of mature lymphocytic neoplasm. The quality of Wright's stain, being short of complete cytochemical stains, lacking of awareness of this disease, and acute leukemia or MDS like appearance in some cases, result in the possibility of diagnostic error as malignant blast, and probably are main causes of misdiagnosis of HSTCL γδ type.


Assuntos
Neoplasias Hepáticas , Linfoma de Células T , Neoplasias Esplênicas , Humanos , Imunofenotipagem , Estudos Retrospectivos
6.
Zhonghua Yi Xue Za Zhi ; 100(11): 837-841, 2020 Mar 24.
Artigo em Chinês | MEDLINE | ID: mdl-32234155

RESUMO

Objective: To evaluate the early diagnostic value of various indicators in the simplified JSTH score criteria for sepsis-associated disseminated intravascular coagulation (DIC). Methods: A retrospective study was conducted. Patients admitted to Intensive Care Unit (ICU) of the Second Affiliated Hospital of Kunming Medical University from January in 2017 to December in 2018 were enrolled. Totally of 365 patients were recruited, with 224 males and 132 females. The simplified JSTH score criteria was used to diagnose DIC. The patients were divided into sepsis with DIC group and sepsis without DIC group according to the diagnostic criteria of sepsis. Platelet (PLT), fibrin degradation products (FDPs), prothrombin time (PT), antithrombin (AT), acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) scores, sequential organ failure assessment (SOFA) scores and the simplified JSTH scores were recorded on the first ICU day. Correlation analyses were conducted.Receiver operating characteristic (ROC) curves for diagnosis of DIC with each indicator were drawn to evaluate the diagnostic efficiency and predictive ability of 28-day mortality. Results: According to the simplified JSTH score, 143 cases of sepsis complicated with DIC were diagnosed. There were significant differences in PLT, FDP, AT, PT, APACHE Ⅱ score, SOFA score, 28-day mortality rate between the two groups (all P<0.01). It was shown by Pearson correlation analysis that the criteria has the best correlation with APACHEⅡ score and SOFA score (r=0.496 and 0.612, both P<0.01). The correlation between PLT and APACHE Ⅱ score or SOFA score was the best (r=-0.440 or-0.568, both P<0.01). It was shown by ROC curve that area under ROC curve (AUC) of PLT was 0.933, and the sensitivity and specificity was 93.0% and 85.0%, respectively. The 28-day mortality was predicted by using the indicators in the criteria. The AUG of AT was 0.813, and both the sensitivity (81.6%) and specificity (73.6%) were the highest. Conclusions: The simplified JSTH score criteria can be used for early diagnosis of sepsis-associated DIC and it is positively correlated with the severity of the disease. The correlation between PLT and the severity of disease is the best, and early diagnosis efficiency of PLT is the strongest. AT has a good predictive value for 28-day mortality.


Assuntos
APACHE , Coagulação Intravascular Disseminada , Diagnóstico Precoce , Sepse , Coagulação Intravascular Disseminada/diagnóstico , Coagulação Intravascular Disseminada/etiologia , Feminino , Humanos , Unidades de Terapia Intensiva , Masculino , Prognóstico , Curva ROC , Estudos Retrospectivos , Sepse/complicações , Sepse/diagnóstico
7.
Zhonghua Zhong Liu Za Zhi ; 41(11): 837-843, 2019 Nov 23.
Artigo em Chinês | MEDLINE | ID: mdl-31770851

RESUMO

Objective: To evaluate the value of T2WI signal intensity related parameters that can be obtained by magnetic resonance imaging (MRI) for predicting pathological complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanved rectal cancer (LARC). Methods: Signal Intensity of Tumor (SIT) and Signal Intensity of Tumor/Muscle (SIT/M) of MR T2WI before and after neoadjuvant chemoradiotherapy of 101 patients with locally advanced rectal cancer were evaluated by two experienced readers independently. Signal Intensity of Tumor Reduction Rate (SITRR) and Signal Intensity of Tumor/Muscle Reduction Rate (SIT/MRR) were calculated. The difference of related parameters of T2WI tumor signal intensity between the pCR and the non-pCR group were analyzed. Receiver operating characteristic (ROC) analysis was used to assess the diagnostic performance for predicting pCR. Results: Of the 101 patients, 18 were in pCR group and 83 were in non-pCR group. In all patients, the SITpre, SITpost, SITRR, SIT/Mpre, SIT/Mpost and SIT/MRR measured by reader 1 were 197.0 (133.0), 144.2 (69.7), 0.4% (0.5%), 2.6 (0.6), 3.0 (2.3) and 0.4 (0.2)% in pCR group, and 227.0 (99.0), 205 (95.4), 0.1% (0.6%), 2.6 (0.6), 2.6 (1) in non-pCR group, respectively. SITpre, SITpost, SITRR, SIT/Mpre, SIT/Mpost and SIT/MRR measured by reader 2 were 193.0 (135.0), 143.0 (69.8), 0.4% (0.2%), 2.6 (0.6), 1.5 (0.5) and 0.39% (0.2%) in pCR group, and 234.0(108.0), 203(96.5), 0.1% (0.3%), 2.6 (0.6%), 1.7 (0.7) and 0.25% (0.2%) in non-pCR group, respectively. Between the pCR and non-pCR group, there were significant differences in SITpost, SIT/Mpost and SIT/MRR measured by both readers (all P<0.01), but there was no significant differences in SITpre and SIT/Mpre (P>0.05). The difference of SITRR measured by reader 1 was not statistically significant (P=0.415), while the difference of SITRR measured by reader 2 was statistically significant (P=0.001). In patients with rectal non-mucinous adenocarcinoma, SITpost, SIT/Mpost, SITRR and SIT/MRR measured by two physicians were still statistically significant between the pCR and non-pCR group (all P<0.01), but SITpre and SIT/Mpre had no significant difference (P>0.05). ROC curve analysis showed that in all patients, the area under curve (AUC) of SITpost, SIT/Mpost and SIT/MRR for predicting pCR to neoadjuvant chemoradiotherapy in locally advanced rectal cancer was 0.694-0.762, the sensitivity was 68.2%-77.3%, and the specificity was 63.6%-77.3%. In rectal non-mucinous adenocarcinoma patients, the AUC, sensitivity and specificity was 0.704-0.764, 62.7%-78.9% and 66.2%-84.2%, respectively. Conclusions: T2WI signal intensity related parameters are potential predictors for pCR in locally advanced rectal cancer after neoadjuvant chemoradiptherapy. The predictive value is higher in non-mucinous adenocarcinoma.


Assuntos
Quimiorradioterapia , Terapia Neoadjuvante , Neoplasias Retais/tratamento farmacológico , Humanos , Imageamento por Ressonância Magnética , Curva ROC , Neoplasias Retais/diagnóstico por imagem , Resultado do Tratamento
8.
Artigo em Chinês | MEDLINE | ID: mdl-31446712

RESUMO

Summary To study the clinical features, diagnosis and treatments of tuberculous otomastoiditis. One case is reported and literatures are reviewed. In this report, the specimen of the middle ear revealed the presence of acid fast bacilli(AFB), grew mycobacterium tuberculosis on a culture. Lung CT scans demonstrated tuberculosis. After anti-tuberculosis therapy, the symptoms disappeared and did not recur in 3 years. Hydrotympanum can be the early symptom of tuberculous otomastoiditis. When persistent otorrhea can not be improved by conventional therapy, tuberculous otomastoiditis should be considered as one of the differential diagnosis.


Assuntos
Mastoidite/diagnóstico , Otite Média com Derrame/etiologia , Tuberculose/diagnóstico , Orelha Média/microbiologia , Orelha Média/patologia , Humanos , Mycobacterium tuberculosis/isolamento & purificação , Tomografia Computadorizada por Raios X
9.
Lin Chuang Er Bi Yan Hou Tou Jing Wai Ke Za Zhi ; 30(15): 1215-1218, 2016 Aug 05.
Artigo em Chinês | MEDLINE | ID: mdl-29798332

RESUMO

Objective:The aim of this study is to investigate the inhibition of nasopharyngeal carcinoma cells by indole-3-carbinol in vitro and in vivo.Method:The human nasopharyngeal carcinoma cell line CNE2 was treated in different concentrations 0,100,200,300 µmol/L of indole-3-carbinol. Then we detected cell proliferation after 0,24,48 and 72 h, apoptosis after 48 h and the levels of PI3K/Akt pathway-related proteins in vitro. The BALB/c nude mice were divided into three groups: prevention group, treatment group and control group. In vivo, the nude mice in every group were inoculated with nasopharyngeal carcinoma cells CNE2, and mice in prevention and treatment groups were given feed containing 0.5% indole-3-carbinol. We investigated the tumoricidal effect of I3C in nude mice , and eight weeks later, the PI3K/Akt pathway-related proteins expressions in tumors from nude mice of each group were detected.Result:With the indole-3-carbinol concentration increased, cell proliferation decreased and apoptosis increased significantly.The levels of PI3K/Akt pathway-related proteins were decreased.In animal experiments, the prevention and treatment group developed smaller tumors, and the expression of PI3K/Akt pathway-related proteins in prevention and treatment groups PI3K/Akt pathway also reduced, compared to control group. Meanwhile, nearly no changes of heart, liver and kidney tissues in all groups were seen in HE staining.Conclusion:Indole-3-carbinol inhibited the growth of nasopharyngeal carcinoma cells and induced apoptosis effectively in vivo and in vitro. The mechanism might be that indole-3-carbinol could suppress PI3K/Akt pathway.


Assuntos
Apoptose/efeitos dos fármacos , Carcinoma/tratamento farmacológico , Proliferação de Células/efeitos dos fármacos , Indóis/farmacologia , Neoplasias Nasofaríngeas/tratamento farmacológico , Animais , Linhagem Celular Tumoral , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Carcinoma Nasofaríngeo , Fosfatidilinositol 3-Quinases , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/efeitos dos fármacos
10.
Genet Mol Res ; 14(2): 6649-63, 2015 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-26125873

RESUMO

The effects of goal-directed fluid therapy, with lactated Ringer's (LR) and 6% hydroxyethyl starch (HES) solution, on hemorrhagic shock dogs are unknown. We aimed to determine the optimal LR: HES ratio for the resuscitation of hemorrhagic shock dogs. Hemorrhagic shock was induced in 40 ventilated dogs by drawing an estimated 60% blood volume. The animals were randomly divided into five groups (N = 8) according to the LR: HES ratio of the resuscitation fluid (3:1, 2:1, 1:1, 1:2, and 1:3), and were then resuscitated for 24 h to reach the stroke volume variation (SVV) and hemoglobin (Hb) goals by fluid infusion and autologous blood perfusion. The extravascular lung water index (EVLWI), pH, partial pressure of oxygen (PaO2), base excess (BE), sodium, chloride, Hb and creatinine clearance (Clearcrea) were checked after 24 h (R24). The EVLWI of the 3:1 group at R24 were higher than that of the 1:3 group and the baseline value (P < 0.05), whereas the PaO2 was lower (P < 0.05). In contrast to the 3:1 group at R24 and baseline, plasma chloride and sodium in the 1:3 and 1:2 groups increased; however, pH, BE, and Clearcrea decreased (P < 0.05). No significant differences were found in the 1:1 and 2:1 groups at R24 compared with baseline (P > 0.05). Resuscitation with LR and HES at 2:1 and 1:1 ratios are superior in maintaining the acid-base, electrolyte, and lung water balances as well as renal function in hemorrhagic shock dogs than at ratios of 3:l, 1:2, and1:3.


Assuntos
Hidratação/métodos , Derivados de Hidroxietil Amido/farmacologia , Soluções Isotônicas/farmacologia , Ressuscitação/métodos , Choque Hemorrágico/terapia , Equilíbrio Ácido-Base/efeitos dos fármacos , Animais , Transfusão de Sangue Autóloga , Cloretos/sangue , Cães , Hemoglobinas/metabolismo , Testes de Função Renal , Consumo de Oxigênio/efeitos dos fármacos , Respiração Artificial , Lactato de Ringer , Choque Hemorrágico/sangue , Choque Hemorrágico/patologia , Sódio/sangue , Volume Sistólico/efeitos dos fármacos
11.
Chem Commun (Camb) ; 50(50): 6660-3, 2014 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-24827873

RESUMO

Palladium has been the focus of recent research on alternative Pt catalysts for the oxygen reduction reaction (ORR). We show that the activity and stability of Pd toward the ORR can be enhanced by Pd-O-oxide covalent bonding when Pd is supported on exfoliated montmorillonite (ex-MMT) nanoplatelets.

12.
Langmuir ; 21(15): 6915-28, 2005 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-16008404

RESUMO

The potential-induced adsorption and self-assembly of 1,3,5-benzene-tricarboxylic acid (TMA) was investigated at the electrified Au(111)/0.05 M H2SO4 interface by in-situ scanning tunneling microscopy (STM) and surface enhanced infrared reflection absorption spectroscopy (SEIRAS) in combination with electrochemical techniques. Depending on the applied electric field, TMA forms five distinctly different, highly ordered supramolecular adlayers on Au(111) surfaces. We have elucidated their real-space structures at the molecular scale. In the potential range -0.25 V < E < 0.20 V, planar-oriented TMA molecules form a hexagonal open-ring honeycomb structure, Ia, a hydrogen-bonded ribbon-type phase, Ib, and a herringbone-type phase, Ic, stabilized by directional hydrogen bonding and weak substrate-adsorbate interactions. Interfacial water molecules are being replaced. In 0.20 V < or = E < 0.40 V, e.g., around the potential of zero charge, and at slightly higher coverages, a close-packed physisorbed adlayer of hydrogen-bonded TMA dimers, II, was observed. Further increase of the electrode potential to positive charge densities causes an orientation change from planar to upright. An initially disordered phase, IIIa, transforms into an ordered, stripelike chemisorbed adlayer, IIIb, of perpendicularly oriented TMA molecules. One carboxylate group per molecule is bound to the electrode surface, while the two other protonated carboxyl groups are directed toward the electrolyte and act as structure-determining components of a hydrogen-bonded two-dimensional ladder-type network. Structural transitions between the various types of ordered molecular adlayers are attributed to (hole) nucleation and growth processes.

13.
J Phys Chem B ; 109(29): 14183-8, 2005 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-16852781

RESUMO

The assembly of small water clusters (H2O)n, n = 1-6, on a graphite surface is studied using a density functional tight-binding method complemented with an empirical van der Waals force correction, with confirmation using second-order Møller-Plesset perturbation theory. It is shown that the optimized geometry of the water hexamer may change its original structure to an isoenergy one when interacting with a graphite surface in some specific orientation, while the smaller water cluster will maintain its cyclic or linear configurations (for the water dimer). The binding energy of water clusters interacting with graphite is dependent on the number of water molecules that form hydrogen bonds, but is independent of the water cluster size. These physically adsorbed water clusters show little change in their IR peak position and leave an almost perfect graphite surface.

14.
Chemphyschem ; 2(10): 617-9, 2001 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-23686881

RESUMO

Information storage flips molecules out: The orientation of individual molecules-vertically or horizontally on a Cu(111) surface-can be controlled in an electrolyte solution by application of an electrode potential. The transition is completely potential dependent, reversible and stable; such are the minimum requirements for computer memory devices. STM images show two orientations of an adlayer of 2,2'-bipyridine.

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