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Helicobacter pylori:Effect of coexisting diseases and update on treatment regimens 被引量:2
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作者 Shen-Shong Chang Hsiao-Yun Hu 《World Journal of Gastrointestinal Pharmacology and Therapeutics》 CAS 2015年第4期127-136,共10页
The presence of concomitant diseases is an independentpredictive factor for non-Helicobacter pylori(H. pylori) peptic ulcers. Patients contracting concomitant diseases have an increased risk of developing ulcer diseas... The presence of concomitant diseases is an independentpredictive factor for non-Helicobacter pylori(H. pylori) peptic ulcers. Patients contracting concomitant diseases have an increased risk of developing ulcer disease through pathogenic mechanisms distinct from those of H. pylori infections. Factors other than H. pylori seem critical in peptic ulcer recurrence in end stage renal disease(ESRD) and cirrhotic patients. However, early H. pylori eradication is associated with a reduced risk of recurrent complicated peptic ulcers in patients with ESRD and liver cirrhosis. Resistances to triple therapy are currently detected using culture-based and molecular methods. Culture susceptibility testing before first- or second-line therapy is unadvisable. Using highly effective empiric first-line and rescue regimens can yield acceptable results. Sequential therapy has been included in a recent consensus report as a valid first-line option for eradicating H. pylori in geographic regions with high clarithromycin resistance. Two novel eradication regimens, namely concomitant and hybrid therapy, have proven more effective in patients with dual-(clarithromycin- and metronidazole-) resistant H. pylori strains. We aim to review the prevalence of and eradication therapy for H. pylori infection in patients with ESRD and cirrhosis. Moreover, we summarized the updated H. pylori eradication regimens. 展开更多
关键词 CONCOMITANT DISEASES HELICOBACTER PYLORI Culture s
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Nosocomial infection and spread of SARS-CoV-2 infection among hospital staff,patients and caregivers
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作者 Chih-Chien Cheng Li-Yun Fann +3 位作者 Yi-Chang Chou Chia-Chen Liu Hsiao-Yun Hu Dachen Chu 《World Journal of Clinical Cases》 SCIE 2022年第34期12559-12565,共7页
BACKGROUND There are difficulties in diagnosing nosocomial transmission of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) infection in hospital settings. Furthermore, mortality of cases of nosocomial infe... BACKGROUND There are difficulties in diagnosing nosocomial transmission of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) infection in hospital settings. Furthermore, mortality of cases of nosocomial infection(NI) with SARS-CoV-2 is higher than that of the general infected population. In the early stage of the pandemic in Taiwan, as patients were not tested for SARS-CoV-2 at admission, NIs often go undetected. Strictly applying the systematic polymerase chain reaction(PCR) screening, as a standard infection control measure was subsequently implemented to reduce NI incidence. However, evidence on risk factors for SARS-CoV-2 NIs among healthcare workers(HCWs) and caregivers is limited.AIM To assess NI incidence of SARS-CoV-2 among hospital staff, hospitalized patients, and caregivers, and the transmission routes of clusters of infection.METHODS This descriptive retrospective analysis at our hospital from May 15 to August 15, 2021 included data on 132 SARS-CoV-2 NIs cases among hospital staff, inpatients, and caregivers who previously tested negative but subsequently identified with a positive SARS-CoV-2 reverse transcriptase-PCR(RT-PCR) test results, or a hospital staff who tested positive following routine SARS-CoV-2 RT-PCR test. Chi-square tests were performed to compare the differences between hospital staff and private caregivers, and between clusters and sporadic infections.RESULTS Overall, 9149 patients and 2005 hospital staff members underwent routine SARS-CoV-2 RT-PCR testing, resulting in 12 confirmed cluster and 23 sporadic infections. Among the index cases of the clusters, three(25%) cases were among hospital staff and nine(75%) cases were among other contacts. Among sporadic infections, 21(91%) cases were among hospital staff and two(9%) cases were among other contacts(P < 0.001). There was an average of 8.08 infections per cluster. The secondary cases of cluster infection were inpatients(45%), hospital staff(30%), and caregivers(25%). Private caregivers constituted 27% and 4% of the clusters and sporadic infections, respectively(P = 0.024);92.3% of them were infected in the clusters. The mortality rate was 0.0%.CONCLUSION The incidence of SARS-CoV-2 infection was relatively high among private caregivers, indicating a need for infection control education in this group, such as social distancing, frequent handwashing, and wearing PPE. 展开更多
关键词 COVID-19 SARS CoV-2 Cross infection INCIDENCE Retrospective studies Infection control
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Enhancement of insulin-producing cell differentiation from embryonic stem cells using pax4-nucleofection method 被引量:10
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作者 Han-Tso Lin Chung-Lan Kao +7 位作者 Kun-Hsiung Lee Yuh-Lih Chang Shih-Hwa Chiou Fu-Ting Tsai Tung-Hu Tsai Dey-Chyi Sheu Larry LT Ho Hung-Hai Ku 《World Journal of Gastroenterology》 SCIE CAS CSCD 2007年第11期1672-1679,共8页
AIM: To enhance the differentiation of insulin producing cell (IPC) ability from embryonic stem (ES) cells in vitro. METHODS: Four-day embryoid body (EB)-formatted ES cells were dissociated as single cells for... AIM: To enhance the differentiation of insulin producing cell (IPC) ability from embryonic stem (ES) cells in vitro. METHODS: Four-day embryoid body (EB)-formatted ES cells were dissociated as single cells for the followed plasmid DNA delivery. The use of NucleofectorTM electroporator (Amaxa biosystems, Germany) in combination with medium-contained G418 provided a high efficiency of gene delivery for advanced selection. Neucleofected cells were plated on the top of fibronectincoated Petri dishes. Addition of Ly294002 and raised the glucose in medium at 24 h before examination.The differentiation status of these cells was monitored by semi-quantitative PCR (SQ-PCR) detection of the expression of relative genes, such as oct-4, sox-17, foxa2, mixll, pdx-1, insulin 1, glucagons and somatostatin. The percentage of IPC population on d 18 of the experiment was investigated by immunohistochemistry (IHC), and the content/secretion of insulin was estimated by ELISA assay. The mice with severe combined immunodeficiency disease (SCID) pretreated with streptozotocin (STZ) were used to eliminate plasma glucose restoration after pax4^+ ES implantation. RESULTS: A high efficiency of gene delivery was demonstrated when neucleofection was used in the present study; approximately 70% cells showed DsRed expression 2 d after neucleofection. By selection of medium-contained G418, the percentage of DsRed expressing cells kept high till the end of study. The pancreatic differentiation seemed to be accelerated by pax4 nucleofection. When compared to the group of cells with mock control, foxa2, mixll, pdxl, higher insulin and somatostatin levels were detected by SQ-PCR 4 d after nucleofection in the group of pax4 expressing plasmid delivery. Approximately 55% of neucleofected cells showed insulin expression 18 d after neucleofection, and only 18% of cells showed insulin expression in mock control. The disturbance was shown by nucleofected pax4 RNAi vector; only 8% of cells expressed insulin 18 d after nucleofection. A higher IPC population was also detected in the insulin content by ELISA assay, and the glucose dependency was demonstrated in insulin secretion level. In the animal model, improvement of average plasma glucose concentration was observed in the group of pax-4 expressed ES of SCID mice pretreated with STZ, but no significant difference was observed in the group of STZ-pretreated SCID mice who were transplanted ES with mock plasmid. CONCLUSION: Enhancement of IPC differentiation from EB-dissociated ES cells can be revealed by simply using pax4 expressing plasrnid delivery. Not only more IPCs but also pancreatic differentiation-related genes can be detected by SQ-PCR. Expression of relative genes, such as foxa 2, mixl 1, pdx-1, insulin 1 and somatostatin after nucleofection, suggests that pax4 accelerates the whole differentiation progress. The higher insulin production with glucose dependent modulation suggests that pax4 expression can drive more mature IPCs. Although further determination of the entire mechanism is required, the potential of pax-4-nucleofected cells in medical treatment is promising. 展开更多
关键词 Diabetes mellitus NUCLEOFECTION pax4 Embryonic stem cells Insulin producing cells
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Characterization of pancreatic stem cells derived from adult human pancreas ducts by fluorescence activated cell sorting 被引量:15
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作者 Han-Tso Lin Shih-Hwa Chiou +6 位作者 Chung-Lan Kao Yi-Ming Shyr Chien-Jen Hsu Yin-Wen Tarng Larry L-T Ho Ching-Fai Kwok Hung-Hai Ku 《World Journal of Gastroenterology》 SCIE CAS CSCD 2006年第28期4529-4535,共7页
AIM: To isolate putative pancreatic stem cells (PSCs) from human adult tissues of pancreas duct using serumfree, conditioned medium. The characterization of surface phenotype of these PSCs was analyzed by flow cyto... AIM: To isolate putative pancreatic stem cells (PSCs) from human adult tissues of pancreas duct using serumfree, conditioned medium. The characterization of surface phenotype of these PSCs was analyzed by flow cytometry. The potential for pancreatic lineage and the capability of β-cell differentiation in these PSCs were evaluated as well. METHODS: By using serum-free medium supplemented with essential growth factors, we attempted to isolate the putative PSCs which has been reported to express nestin and pdx-1. The MatrigelTM was employed to evaluate the differential capacity of isolated cells. Dithizone staining, insulin content/secretion measurement, and immunohistochemistry staining were used to monitor the differentiation. Fluorescence activated cell sorting (FACS) was used to detect the phenotypic markers of putative PSCs. RESULTS: A monolayer of spindle-like cells was cultivated. The putative PSCs expressed pdx-1 and nestin. They were also able to differentiate into insulin-, glucagon-, and somatostatin-positive cells. The spectrum of phenotypic markers in PSCs was investigated; a similarity was revealed when using human bone marrow-derived stem cells as the comparative experiment, such as CD29, CD44, CD49, CD50, CD51, CD62E, PDGFR-α, CD73 (SH2), CD81, CD105(SH3). CONCLUSION: In this study, we successfully isolated PSCs from adult human pancreatic duct by using serumfree medium. These PSCs not only expressed nestin and pdx-1 but also exhibited markers attributable to mesenchymal stem cells. Although work is needed to elucidate the role of these cells, the application of these PSCs might be therapeutic strategies for diabetes mellitus. 展开更多
关键词 Putative pancreas stem cell Nestirr pdx-1 Phenotypic marker
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Renal function and physical fitness after 12-mo supervised training in kidney transplant recipients 被引量:6
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作者 Giulio Sergio Roi Giovanni Mosconi +20 位作者 Valentina Totti Maria Laura Angelini Erica Brugin Patrizio Sarto Laura Merlo Sergio Sgarzi Michele Stancari Paola Todeschini Gaetano La Manna Andrea Ermolao Ferdinando Tripi Lucia Andreoli Gianluigi Sella Alberto Anedda Laura Stefani Giorgio Galanti Rocco Di Michele Franco Merni Manuela Trerotola Daniela Storani Alessandro Nanni Costa 《World Journal of Transplantation》 2018年第1期13-22,共10页
AIM To evaluate the effect of a 12-mo supervised aerobic and resistance training, on renal function and exercise capacity compared to usual care recommendations.METHODS Ninety-nine kidney transplant recipients(KTRs) w... AIM To evaluate the effect of a 12-mo supervised aerobic and resistance training, on renal function and exercise capacity compared to usual care recommendations.METHODS Ninety-nine kidney transplant recipients(KTRs) were assigned to interventional exercise(Group A; n = 52) and a usual care cohort(Group B; n = 47). Blood and urine chemistry, exercise capacity, muscular strength, anthropometric measures and health-related quality of life(HRQo L) were assessed at baseline, and after 6 and 12 mo. Group A underwent a supervised training three times per week for 12 mo. Group B received only general recommendations about home-based physical activities.RESULTS Eighty-five KTRs completed the study(Group A, n = 44; Group B, n = 41). After 12 mo, renal function remained stable in both groups. Group A significantly increased maximum workload(+13 W, P = 0.0003), V'O2 peak(+3.1 mL/kg per minute, P = 0.0099), muscular strength in plantar flexor(+12 kg, P = 0.0368), height in the countermovement jump(+1.9 cm, P = 0.0293) and decreased in Body Mass Index(-0.5 kg/m^2, P = 0.0013). HRQo L significantly improved in physical function(P = 0.0019), physical-role limitations(P = 0.0321) and social functioning scales(P = 0.0346). Noimprovements were found in Group B.CONCLUSION Twelve-month of supervised aerobic and resistance training improves the physiological variables related to physical fitness and cardiovascular risks without consequences on renal function. Recommendations alone are not sufficient to induce changes in exercise capacity of KTRs. Our study is an example of collaborative working between transplant centres, sports medicine and exercise facilities. 展开更多
关键词 KIDNEY TRANSPLANT RECIPIENTS RENAL function Supervised EXERCISE AEROBIC EXERCISE Muscle strength
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Ultrasound Causes of Female Infertility at the Fertilia Medical Clinic in Bamako 被引量:2
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作者 Mamadou Dembele Alassane Kouma +12 位作者 Ilias Guindo Zoumana Cheick Berete Souleymane Sanogo Mamadou N'diaye Brahima Doumbia Oncoumba Diarra Ousmane Traore Issa Cisse Aboubacar Sidiki N’ Diaye Badiougou Doucoure Youssouf Yalcouye Adama Diaman Keita Siaka Sidibe 《Open Journal of Medical Imaging》 2023年第3期107-113,共7页
Aims: Infertility is a major problem in our current societies and the Fertilia medical clinic in Bamako is a center for medical assistance in procreation (MAP) where there is an increasingly growing demand for ultraso... Aims: Infertility is a major problem in our current societies and the Fertilia medical clinic in Bamako is a center for medical assistance in procreation (MAP) where there is an increasingly growing demand for ultrasound. The objective of our study was to investigate the ultrasound causes likely to prevent the occurrence of pregnancy in a group of infertile and subfertile women. Subjects and Methods: This was a 5-year cross-sectional and prospective study, between January 2017 and January 2022, which involved 250 women wishing to become pregnant (infertile or subfertile), who came for pelvic ultrasound or follicular monitoring and who agreed to participate in our study. The parameters used were ultrasound reports including uterine, ovarian and tubal pathologies. It should be noted that in some cases no ultrasound cause of infertility was found. Data were entered and analyzed in SPSS. Results: 250 women were recruited into our. The average age was 32 years with extremes ranging from 17 to 51 years. 179 patients or 71.6% were between 17 and 35 years old. 139 patients or 55.6% had secondary infertility against 44.4% primary infertility. 202 patients or 80.8% had at least one ultrasound lesion and 48 patients or 19.2% had no significant ultrasound abnormality. The most represented ultrasound lesions were of uterine origin with 72.20%, 23.7% ovarian lesions and 04% tubal lesions. Uterine lesions were dominated by myomas, adenomyosis, endometrial polyps, uterine malformations and synechiae. As for ovarian lesions we noted cysts, polycystic ovary syndrome (PCOS), ovarian endometriosis, non-follicular ovaries and tubal ultrasound lesions showed unilateral or bilateral hydrosalpinx. Conclusion: In our study, ultrasound was an invaluable contribution to the diagnosis of the causes likely to explain subfertility and infertility in our respondents. She highlighted uterine, ovarian and tubal lesions, some of which could be corrected and pregnancies ensued. 展开更多
关键词 ULTRASOUND Female Infertility MYOMAS Polycystic Ovaries HYDROSALPINX
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Microglia-conditioned medium promotes locomotor recovery and neuroprotection after rat spinal cord injury
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作者 May-Jywan Tsai Pei-Jou Ho +6 位作者 Yi-Lo Lin Ming-Chao Huang Meng-Jen Lee Dann-Ying Liou Wen-Cheng Huang Yu-Show Fu Henrich Cheng 《Advances in Bioscience and Biotechnology》 2012年第4期524-530,共7页
This work examines whether microglia-conditioned medium (MCM) is beneficial in stressed spinal cord cells or tissues. MCM was separated into two fractions by 50 kDa molecular cut-off centrifugation. MCM not only promo... This work examines whether microglia-conditioned medium (MCM) is beneficial in stressed spinal cord cells or tissues. MCM was separated into two fractions by 50 kDa molecular cut-off centrifugation. MCM not only promoted survival of neuronal and oligodendroglial cells but effectively reduced LPS stimulation in spinal cord cultures. We further utilized the NYU weight-drop device to induce contusive spinal cord injury (SCI) in rats. Immediately after dropping the impactor from a height of 25 mm onto thoracic spinal segment, MCM was intrathecally administered. At 6 weeks post-injury, SCI rats receiving MCM > 50 kDa treatment showed significant hind-limb improvement over MCM 50 kDa, of microglia was neuroprotective against spinal cord injury. 展开更多
关键词 MICROGLIA NEUROPROTECTION SPINAL CORD ANTI-INFLAMMATION
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Varicocele and Spermogram Abnormality: About 264 Cases at the Fertilia Medical Clinic in Bamako
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作者 Mamadou Dembélé Alassane Kouma +12 位作者 Ilias Guindo Souleymane Sanogo Zoumana Cheick Berete Ousmane Traoré Mamadou N’diaye Brahima Doumbia Oncoumba Diarra Issa Cissé Aboubacar Sidiki N’diaye Bandiougou Doucouré Youssouf Yalcouyé Adama Diaman Keita Siaka Sidibe 《Open Journal of Medical Imaging》 2023年第3期84-91,共8页
Aims: To determine the impact of varicocele on the result of the spermogram in a group of hypo-fertile or infertile men. Patients and Method: This was a cross-sectional, descriptive study concerning 264 men collected ... Aims: To determine the impact of varicocele on the result of the spermogram in a group of hypo-fertile or infertile men. Patients and Method: This was a cross-sectional, descriptive study concerning 264 men collected between February 2020 and March 2022 at the Fertilia medical clinic in Bamako. The study population consisted of consenting male subjects presenting for infertility. All of our patients had already done a spermogram, they then benefited from a scrotal Doppler ultrasound. The scrotal echo-doppler was completed by an abdominal and pelvic echography in search of a possible etiology, in particular a renal cancer, a thrombosis of the renal or spermatic vein, a retroperitoneal mass or a nutcraker syndrome. Testicular volume was measured on ultrasound according to Lambert’s formula (length × width × height × 0.71). A volume = 16 ml was considered normal. Results: 264 patients were recruited in ours. The average age was 33 years with extremes ranging from 25 to 65 years. 149 patients or 56.44% were between 30 and 45 years old. 213 patients or 80.68% had primary infertility. All the patients, i.e. 100%, had a sperm anomaly and dilation of the pampiniform plexus veins. The most common sperm abnormalities were oligoasthenoteratozoospermia, which concerned 214 patients, or 81%, followed by azoospermia (40 patients, or 15%) and oligospermia (10 patients, or 4%). 213 patients or 80.68% had a Hirshen grade II varicocele, 45 patients or 17% had grade I and 06 patients or 2.27% had grade III. Among the 6 patients, 04 had left testicular atrophy and 2 bilateral atrophy. The venous reflux was more accentuated on the left than on the right. Conclusion: Varicocele is significantly found in men with infertility. Sperm alterations concern both the concentration of spermatozoa, their mobility and their vitality. Even if the mechanism of alteration of the sperm parameters is not well elucidated, our study made it possible to make the link between the dilation of the veins of the pampiniform plexus and the sperm abnormalities mentioned above. It should be recognized that varicocelectomy has allowed a significant improvement in the quality of sperm with the obtaining of a certain number of natural pregnancies and those resulting from medically assisted procreation. 展开更多
关键词 ULTRASOUND Male Infertility VARICOCELE OLIGOASTHENOTERATOZOOSPERMIA
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Endometrial Status and Embryonic Implantation about 150 Cases at the Medically Assisted Procreation Laboratory “Le Diafounou”
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作者 Mamadou Dembélé Alassane Kouma +12 位作者 Ilias Guindo Souleymane Sanogo Zoumana Cheick Berete Ousmane Traoré Mamadou N’Diaye Brahima Doumbia Oncoumba Diarra Issa Cissé Aboubacar Sidiki N’diaye Bandiougou Doucouré Youssouf Yalcouyé Adama Diaman Keita Siaka Sidibe 《Open Journal of Medical Imaging》 2023年第3期92-100,共9页
Background: The endometrium is the tissue that lines the inside of the uterus. It undergoes multiple changes during the menstrual cycle and prepares to welcome the fertilized egg. Endovaginal ultrasound is a first-lin... Background: The endometrium is the tissue that lines the inside of the uterus. It undergoes multiple changes during the menstrual cycle and prepares to welcome the fertilized egg. Endovaginal ultrasound is a first-line examination in the assessment of female infertility. Objective: We aimed to determine the impact of endometrial status by endovaginal ultrasound on the outcome of embryo transfers. Subjects and Methods: This was a prospective cross-sectional study of 150 women collected between January and October 2020 at the “Le Diafounou” medically assisted procreation laboratory. Were included in the study, women presenting for desire of pregnancy and having continued the treatment until the transfer of fresh or frozen embryos. An uterine score was used. This score took into account the thickness of endometrium, it is coffee bean aspect, the presence of the notch, the echogenicity of the endometrium, the pulsatility index, the presence of the flow at the end of diastole and sub-endometrial flow. Ultrasounds were performed using a General Electric logic 500, logic 9 and Voluson E8 device. The data was entered into Excel and then analyzed using SPSS version 21. Results: 150 women were selected for the study. 83 women or 55.3% were between 17 and 35 years old and 44.7% were over 35 years old with an upper limit of 50 years old. The number of women who became pregnant was 69% or 46%. The average thickness of the endometrium was 11.40 mm with extremes of 4.65 mm and 18.6 mm. There was a correlation between the thickness of the endometrium and obtaining a pregnancy (p i.e. 88.7%. The pulsatility index was relatively low for those who started a pregnancy, i.e. 90%. The high pulsatility index is one of the reasons for the failure of embryo implantation. The correlation was significant (p = 0.009). 141 women had no notch in the uterine arteries, i.e. 94%. 94 women or 62.7% had a triple line endometrium or typical coffee bean appearance. End-diastolic flow was observed in 127 women, i.e. 84.7%. The sub-endometrial flow was found in 128 women or 85.3%. Conclusion: The Knowledge of the status of the endometrium is essential and has an impact on the outcome of embryo transfers. The thinner (7 and <15). Doppler factors also play an important role. 展开更多
关键词 Endometrial Status Embryonic Implantation Medically Assisted Procreation
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Effects of clinical dental implant abutment materials and their surface characteristics on initial bacterial adhesion 被引量:7
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作者 Yu-Shan Huang Her-Hsiung Huang 《Rare Metals》 SCIE EI CAS CSCD 2019年第6期512-519,共8页
Initial bacterial adhesion on dental implant abutment is related to its surface chemical composition and physical characteristics.Selection of appropriate abutment materials resistant to bacterial adhesion is importan... Initial bacterial adhesion on dental implant abutment is related to its surface chemical composition and physical characteristics.Selection of appropriate abutment materials resistant to bacterial adhesion is important for dental implant maintenance.The aim of present study was to evaluate the effect of different properties of abutment materials on initial bacterial adhesion in vitro.Polished zirconia(PZ group), polished titanium(PT group) and ground titanium(GT group) samples were prepared to simulate clinical dental implant abutments.Chemical compositions, morphology, roughness, hydrophilicity and surface free energy of materials were analyzed.Oral commensal bacterium Streptococcus mitis was used to evaluate initial bacterial adhesion via turbidity test and colony-forming unit counting.The results showed that GT group presented the highest roughness, hydrophilicity and surface free energy.After 6-h incubation, GT group showed the significantly highest adhered bacteria counts;while non-significant difference existed between PT and PZ groups.Within the clinically applicable range used in present study, the surface physical characteristics, instead of surface chemical composition, of dental abutment material have the pronounced influence on initial 6-h bacterial adhesion. 展开更多
关键词 DENTAL IMPLANT ABUTMENT BACTERIAL ADHESION ZIRCONIA Titanium Surface characteristics
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Modulating the synergy of Pd@Pt core-shell nanodendrites for boosting methanol electrooxidation kinetics
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作者 Hyeon Jeong Kim Cheol Joo Moon +4 位作者 Seokhee Lee Jayaraman Theerthagiri Jong Wook Hong Myong Yong Choi Young Wook Lee 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2023年第34期153-160,共8页
The single-pot production of Pd@Pt core-shell structures is a promising approach as it offers large surface area,catalytic capability,and stability.In this work,we established a single-pot process to produce Pd@Pt cor... The single-pot production of Pd@Pt core-shell structures is a promising approach as it offers large surface area,catalytic capability,and stability.In this work,we established a single-pot process to produce Pd@Pt core-shell nanodendrites with tunable composition,shape and size for optimal electrochemical activity.Pd@Pt nanodendrites with diverse compositions were synthesized by tuning the ratios of Pd and Pt sources in an aqueous environment using cetyltrimethylammonium chloride,which functioned as both the surfactant and the reducing agent at an elevated temperature(90°C).The synthesized Pd5@Pt5 nanodendrites showed exceptional electrochemical action toward the methanol oxidation reaction related with another compositional Pd@Pt nanodendrites and conventional Pt/C electrocatalysts.In addition,Pd5@Pt5 nanodendrites exhibited good CO tolerance owing to their surface features and the synergistic effect among Pt and Pd.Meanwhile,nanodendrites with a Pt-rich surface provided exceptional catalytic active sites.Compared with the conventional Pt/C electrocatalyst,the anodic peak current obtained by Pd5@Pt5 nanodendrites was 3.74 and 2.18 times higher in relations of mass and electrochemical active surface area-normalized current density,respectively.This approach offers an attractive strategy to design electrocatalysts with unique structures and outstanding catalytic performance and stability for electrochemical energy conversion. 展开更多
关键词 Core-shell nanostructure Pd@Pt electrocatalysis One-pot synthesis Formation mechanism of nanodendrites Methanol oxidation reaction
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