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2.
Zhonghua Bing Li Xue Za Zhi ; 49(2): 134-138, 2020 Feb 08.
Artigo em Chinês | MEDLINE | ID: mdl-32074725

RESUMO

Objective: To investigate the clinicopathological manifestations, molecular genetic, diagnostic histology and differential diagnosis of alveolar soft part sarcoma (ASPS) in children. Methods: A total of 13 cases of ASPS diagnosed at Beijing Children's Hospital from August 2009 to November 2018 were collected. HE staining, histochemical staining for PAS and D-PAS, immunohistochemical (IHC) staining for TFE3, INI1 and CD68 and florescence in situ hybridization (FISH) for TFE3 gene translocation were performed. Results: There were four males and nine females, age ranged from 1 year and 2 months to 13 years and 8 months (mean 7.8 years); and four patients were under 5 years old. Histologically, the tumors showed a distinctive and characteristic nested or organoid growth pattern (11 cases) or solid, diffuse growth (2 cases). The tumor cells possessed abundant eosinophilic, or glycogen-rich and clear to vacuolated cytoplasm. The chromatin was relatively dispersed, with prominent and pleomorphic nucleoli; mitotic figures were rare. Vascular invasion was frequently seen. IHC staining showed specific nuclear TFE3 staining. The tumor cells were also positive for INI1,CD68 and vimentin; but were negative for MyoD1, Myogenin, CK and S-100 protein. Seven cases showed PAS and D-PAS staining, with fuchsia acicular or rod-shaped crystals in tumor cytoplasm. Nine cases showed TFE3 break-apart signals by FISH. Conclusions: ASPS is a rare soft tissue sarcoma in children. Compared with ASPA in adults, it has both similarities and unique clinicopathologic characteristics. The diagnosis needs to be confirmed by combining clinical, pathologic, IHC and genetic testing.

4.
Plant Dis ; : PDIS03190435RE, 2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31944880

RESUMO

Anthracnose is a devastating disease that seriously affects pepper production worldwide. Anthracnose management is currently a major problem because of the widespread and long period of infection of this disease. Therefore, determination of the optimal fungicide application timing is important for controlling anthracnose in a timely manner . In vitro sensitivity tests showed no significant difference in the pyraclostrobin sensitivity of Colletotrichum scovillei collected from 2016 and 2017, with mean half maximal effective concentration values of 0.349 to 0.542 and 0.0475 to 0.0639 mg/liter for the inhibition of mycelial growth and spore germination, respectively. Fungicide application initiated at the full-bloom stage could significantly delay anthracnose disease onset, decrease anthracnose incidence and development (23.67 to 89.80%), and increase pepper yield by 10.7 to 29.2%. In addition, the application dosage was decreased by >50%. BF-500-3, the main metabolite of pyraclostrobin, was detected in pepper fruit and exhibited high inhibitory activity against C. scovillei. The final residues of all fungicides at different application timing were below maximum residue limits. Moreover, structural equation modeling indicated that application timing plays the most important role in anthracnose disease inhibition. The tank mixtures of pyraclostrobin with tebuconazole and fludioxonil showed more satisfactory efficacy (69.87 to 78.36%) against anthracnose than did pyraclostrobin alone under field conditions. This study is the first to determine the best fungicide application timing for anthracnose management. These results establish the basis for sustainable development of the pepper industry.

5.
J Helminthol ; 94: e118, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31959266

RESUMO

Glutathione S-transferases (GSTs) are a detoxifying enzyme family that is essential for parasite blood-feeding and survival, and represent potential targets for hookworm vaccine development. Multiple GST-encoding complementary DNAs (cDNAs) have been cloned from Ancylostoma caninum and Necator americanus, but there are no reports about the cloning of this enzyme from Ancylostoma ceylanicum, the animal-derived zoonotic hookworm. To study the molecular nature and tissue localization of GST of A. ceylanicum (Ace-GST), we designed primers based on the GST gene sequence of A. ceylanicum in GenBank, amplified the Ace-GST cDNA by reverse transcription polymerase chain reaction, and analysed its homology and genetic evolution relationship. The amplified product was cloned into the pET-32a vector and transformed into Escherichia coli BL21 (DE3) for expression. To prepare anti-GST polyclonal antibodies, the recombinant protein was purified and used to immunize Kunming mice. The level of immunoglobulin G (IgG) antibody in the serum of immunized mice was detected by indirect enzyme-linked immunosorbent assay, and the Ace-GST localization in adult worm was determined using the immunofluorescence method. The results showed that the full-length cDNA encoding Ace-GST was 468 bp, which had the highest homology with Ac-GST-1 (60.1%) and clustered into one branch (v-class) with Ac-GST-1 and Na-GST-1 in a phylogenetic tree. Mice immunized with recombinant Ace-GST showed specific IgG antibody response. Immunolocalization revealed that natural Ace-GST is mainly located in the epidermis, muscle and intestine of the adult. These results may lay a foundation for further studies on the biological function of Ace-GST.

6.
Qual Life Res ; 29(1): 19-36, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31620985

RESUMO

PURPOSE: To systematically review studies investigating health-related quality-of-life (HrQoL) in patients with premature ovarian insufficiency (POI), to examine questionnaires used and to conduct a meta-analysis of control studies with normal ovarian function. METHODS: Data sources: PubMed, Embase, Web of science, CNKI, and CQVIP, searched from inception until June 2018. The search strategy was a combination of medical (e.g. POI), subjective (e.g. well-being) and methodological (e.g. questionnaires) keywords. PRISMA guidelines were used to assess outcome data quality/validity by one reviewer, verified by a second reviewer. Risk of bias within studies was evaluated. A meta-analysis compared HrQoL in patients and non-patients. Due to measurement differences in the studies, the effect size was calculated as standard mean difference. RESULTS: We identified 6869 HrQoL studies. Nineteen geographically diverse studies met inclusion criteria, dated from 2006, using 23 questionnaires. The meta-analysis included six studies with 645 POI participants (age 33.3 ± 5.47) and 492 normal-ovarian control subjects (age 32.87 ± 5.61). Medium effect sizes were found for lower overall HrQoL (pooled SMD = - 0.73, 95% CI - 0.94, - 0.51; I2 = 54%) and physical function (pooled SMD = - 0.54, 95% CI - 0.69, - 0.39; I2 = 55%). Heterogeneity was investigated. Effect sizes varied for sexual function depending on the measure (SMD = - 0.27 to - 0.74), overall HrQoL (SF-36) had the largest effect size (- 0.93) in one study. The effect sizes for psychological and social HrQoL were small. CONCLUSION: POI is associated with low-to-medium effect size on HrQoL compared to normal ovarian controls. The greatest effects are found in general HrQoL and most sexual function areas. Condition-specific questionnaires and RCTs are recommended for further investigation.

7.
Plant Dis ; 104(2): 551-559, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31859594

RESUMO

Anthracnose caused by Colletotrichum scovillei is one of the most destructive diseases affecting chili production. Disease control mainly relies on conventional fungicides, and repeated exposure to single-site mode-of-action fungicides may pose a risk for the development of resistant isolates within the population. Our previous study suggested that pyrisoxazole has strong inhibitory activity against C. scovillei in vitro. However, the effects of pyrisoxazole on the C. scovillei infection process and the performance of pyrisoxazole in the field remain unclear. In this study, pyrisoxazole exhibited strong inhibitory activity against the mycelial growth, appressorium formation, and appressorium diameter of C. scovillei, with half maximal effective concentration values of 0.1986, 0.0147, and 0.0269 µg/ml, respectively, but had no effect on sporulation, even at the highest concentration of 1.6 µg/ml. The baseline sensitivity curves were unimodal with a long right-hand tail. The in vivo data showed that pyrisoxazole provided both preventive and curative activity against anthracnose on chili. Pyrisoxazole decreased the incidence of anthracnose and reduced disease progress. The results of electron microscopy showed that pyrisoxazole can affect the C. scovillei infection process by altering mycelial morphology, degrading conidia and germ tubes, suppressing conidial germination and appressorium formation, and enhancing conidiophore production. Pyrisoxazole can be used to effectively control anthracnose under field conditions and increase chili yield; moreover, no phytotoxicity symptoms were observed after treatment. These results provide new insight into the mechanisms by which pyrisoxazole controls disease and suggest that pyrisoxazole is a feasible alternative for the management of anthracnose in chili.

9.
Zhonghua Wai Ke Za Zhi ; 57(12): 917-920, 2019 Dec 01.
Artigo em Chinês | MEDLINE | ID: mdl-31826596

RESUMO

Objective: To examine the effectiveness of non-operative of colonic fistula following acute pancreatitis. Methods: Retrospective analysis of 354 patients with acute pancreatitis who were admitted to Department of Hepatobiliary Surgery of Chinese People's Liberation Army General Hospital from January 2013 to December 2018. Age of the patients was (46±14) years (range: 14-85 years); 249 cases (70.3%) were males. There were 41 cases of acute edematous pancreatitis and 313 cases of acute necrotising pancreatitis. Two hundred and fifteen cases were diagnosed as moderate severe acute pancreatitis and 139 were diagnosed as severe acute pancreatitis. Among 313 cases of acute necrotising pancreatitis, 62 cases underwent non-surgical treatment, 251 cases underwent surgical treatment in which 218 of minimal access retroperitoneal pancreatic necrosectomy underwent percutaneous nephroliguectomy with peripancreatic necrotic tissue removal technique. Results: There were 15 cases of colon fistula following acute necrotising pancreatitis, and the incidence rate was 4.2%(15/354). There were 7 males and 8 females, with age of (39±8) years (range: 27 to 50 years). The median interval between acute pancreatitis onset and diagnosis of colonic fistula was 71 days(27-134) days. Two cases occurred at the hepatic flexure of the colon, 4 cases at transverse colon, and 9 cases at splenic flexure of colon. Of the 354 patients, 39 cases died and the mortality was 11.0%. Two patients underwent laparotomy, and one of them died. The remaining 13 patients underwent non-surgical treatment and were discharged. Conclusion: Acute pancreatitis with colonic fistula can be treated with non-surgical treatment and can achieve good prognosis.


Assuntos
Doenças do Colo/terapia , Fístula Intestinal/terapia , Pancreatite/terapia , Doença Aguda , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Doenças do Colo/etiologia , Feminino , Humanos , Fístula Intestinal/etiologia , Masculino , Pessoa de Meia-Idade , Pancreatite/complicações , Pancreatite Necrosante Aguda/complicações , Pancreatite Necrosante Aguda/terapia , Prognóstico , Estudos Retrospectivos , Adulto Jovem
10.
Phys Rev Lett ; 123(22): 221301, 2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31868422

RESUMO

We present results on light weakly interacting massive particle (WIMP) searches with annual modulation (AM) analysis on data from a 1-kg mass p-type point-contact germanium detector of the CDEX-1B experiment at the China Jinping Underground Laboratory. Datasets with a total live time of 3.2 yr within a 4.2-yr span are analyzed with analysis threshold of 250 eVee. Limits on WIMP-nucleus (χ-N) spin-independent cross sections as function of WIMP mass (m_{χ}) at 90% confidence level (C.L.) are derived using the dark matter halo model. Within the context of the standard halo model, the 90% C.L. allowed regions implied by the DAMA/LIBRA and CoGeNT AM-based analysis are excluded at >99.99% and 98% C.L., respectively. These results correspond to the best sensitivity at m_{χ}<6 GeV/c^{2} among WIMP AM measurements to date.

12.
Beijing Da Xue Xue Bao Yi Xue Ban ; 51(6): 1115-1118, 2019 Dec 18.
Artigo em Chinês | MEDLINE | ID: mdl-31848514

RESUMO

OBJECTIVE: To explore the relationships of periodontal parameters, cortical width on mental foramen and osteoporotic condition in postmenopausal women. METHODS: Ninetyeight postmenopausal women between 50 to 65 years old were recruited. General conditions, such as age, menopausal age, duration of menopause, and body mass index (BMI) were recorded. Periodontal parameters were examined, including oral hygiene index simplified (OHI-S), probing depth (PD), clinical attachment loss (CAL), gingival recession (GR) and bleeding on probing (BOP). Panoramic radiograph was taken and the cortical width (CW) of mental foramen was measured on images. The examiner was celebrated. Bone mass density (BMD) of left hip and lumbar spine was assessed using standardized dual energy X-ray absorptiometry. According to World Health Organization, based on the T-score of BMD (difference of the measured BMD and the mean value of young white women in terms of standard deviations), the subjects were divided into osteoporotic group (T-score<-2.5) and non-osteoporotic group (T-score≥-2.5). These parameters were compared between the groups. RESULTS: The number of osteoporotic group was 47 (47.96%). Ages and duration of menopause were significantly different between the groups. Osteoporotic group presented older ages [(59.64±4.58) years vs. (56.94 ± 4.26) years, P<0.05], and longer duration of menopause [(10.17± 5.37) years vs. (6.02 ±4.48) years, P<0.05]. There was no significant difference in menopausal age and BMI between the groups. BOP% was statistically significantly higher in osteoporotic group (29.43±21.12) than in non-osteoporotic group (21.43±17.09), with a P-value of 0.046. The other periodontal parameters, including OHI-S, PD, CAL, and GR were not statistically significantly different in the groups. The CWs were statistically significantly lower in osteoporotic group compared with non-osteoporotic group, with a P-value of 0.001. The mean values of CWs were (3.61±1.04) mm (osteoporotic group) and (4.25±0.77) mm (non-osteoporotic group), respectively. CONCLUSION: The study demonstrated absence of a significant association between periodontal parameters and BMD. However, the CWs were found to be related with the BMD, which may be used to detect BMD abnormal in maxillofacial imaging. The dentists should pay attention not only to the oral health, but also to the general bone mass density, which may be detected on panoramic images.


Assuntos
Osteoporose Pós-Menopausa , Periodontite , Absorciometria de Fóton , Idoso , Densidade Óssea , Feminino , Humanos , Pessoa de Meia-Idade , Pós-Menopausa
14.
Zhonghua Bing Li Xue Za Zhi ; 48(11): 851-855, 2019 Nov 08.
Artigo em Chinês | MEDLINE | ID: mdl-31775433

RESUMO

Objective: To investigate the clinical, pathological features and differential diagnosis of testicular Leydig cell hyperplasia (LCH) . Methods: Clinical data, histological features, immunohistochemical findings, ultrastructural characteristics and follow-up data were analyzed in three cases of LCH. The cases were collected from 2011 to 2014 at Beijing Children's Hospital. A literature review was performed. Results: Two males (1.8 years and 2.9 years of age) showed isosexual pseudoprecocity with elevated serum testosterone. Imaging study showed bilateral testicular enlargement with multiple small nodules in the parenchyma. Another 13 years-old patient showed male pseudohermaphroditism and cryptorchism. Gross examination showed the bilateral markedly enlarged testis without discrete lesion. Histologically, LCH was seen in both nodular and diffuse patterns without destruction of seminiferous tubules. Adjacent spermatogenesis was noted. Immunohistochemically, the Leydig cells were positive for inhibin, calretinin and Melan A and ultrastructural analysis showed enriched cytoplasmic endoplasmic reticulum. Two cases had followed up for 7 years. One patient was symptom-free and one was stable. Conclusion: LCH is a rare benign condition, which is easily misinterpreted as testicular tumor or non-neoplastic diseases. Clinical presentation, imaging study and pathological evaluation are required for the diagnosis.


Assuntos
Células Intersticiais do Testículo/patologia , Doenças Testiculares/patologia , Testículo/patologia , Adolescente , Pré-Escolar , Humanos , Hiperplasia , Lactente , Masculino
15.
Phys Rev Lett ; 123(16): 161301, 2019 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-31702340

RESUMO

We report results on the searches of weakly interacting massive particles (WIMPs) with sub-GeV masses (m_{χ}) via WIMP-nucleus spin-independent scattering with Migdal effect incorporated. Analysis on time-integrated (TI) and annual modulation (AM) effects on CDEX-1B data are performed, with 737.1 kg day exposure and 160 eVee threshold for TI analysis, and 1107.5 kg day exposure and 250 eVee threshold for AM analysis. The sensitive windows in m_{χ} are expanded by an order of magnitude to lower DM masses with Migdal effect incorporated. New limits on σ_{χN}^{SI} at 90% confidence level are derived as 2×10^{-32}∼7×10^{-35} cm^{2} for TI analysis at m_{χ}∼50-180 MeV/c^{2}, and 3×10^{-32}∼9×10^{-38} cm^{2} for AM analysis at m_{χ}∼75 MeV/c^{2}-3.0 GeV/c^{2}.

16.
Zhonghua Lao Dong Wei Sheng Zhi Ye Bing Za Zhi ; 37(10): 768-772, 2019 Oct 20.
Artigo em Chinês | MEDLINE | ID: mdl-31726509

RESUMO

Objective: To investigate the visual application of the CiteSpace software in the field of work-related musculoskeletal disorders (WMSDs) . Methods: The literature on WMSDs research, published from 1991 to 2017, was retrieved in Web of Science database. The CiteSpace 5.2 was used to make visualization analysis on the hotspots and tendency of the keywords, authors, countries (regions) and research institutes in relevant literature. Results: A total of 3224 literatures were included in the analysis. The amount of the literatures published was increasing annually. The key word co-occurrence network showed that the research hotspots mainly focused on the study of epidemiology, risk factors, symptoms, and other aspects of WMSDs. The cooperation network and time network of counties and regions showed that America and Europe were at the leading position in the field of WMSD, and the top three were America, Canada and Sweden. The developing countries, like Brazil and China, had also begun to make relative research since 2000. In research cooperation, the collaboration among countries, research institutions was relatively close, and multiple leading core authors and teams were formed in the international arena. Conclusion: The CiteSpace software can directly demonstrate the hotspots and tendency in the area of WMSDs.


Assuntos
Diagnóstico por Computador , Doenças Musculoesqueléticas/diagnóstico , Doenças Profissionais/diagnóstico , Software , Humanos
17.
Zhonghua Liu Xing Bing Xue Za Zhi ; 40(10): 1296-1303, 2019 Oct 10.
Artigo em Chinês | MEDLINE | ID: mdl-31658534

RESUMO

Objective: In this study, a systematic review was made on scientific evidence regarding the impact of food environment on diet-related behavior and obesity in China. Methods: Search on related keywords and references were conducted from four electronic databases including the Cochrane Library, PubMed, Web of Science, and CNKI. Results: Data showed that good availability, accessibility of neighborhood food outlets had increased the diversity of food, including the intakes of total calories, protein, fat, and carbohydrate; however, the consumption of healthy foods such as fruit and vegetables was reducing among the Chinese residents. The effects of neighborhood food environment on obesity remained inconclusive. A large number of fast food restaurants around schools might be responsible for the increase of risk on obesity among students. Regulations set on the school vicinity food stalls might reduce the intake of sugary beverages, snacks and fast food among students. Conclusion: Building a healthy food environment is warranted to nudge the Chinese people towards a healthier diet pattern. However, more evidence is needed to support the evidence in building a healthy food environment.


Assuntos
Dieta , Obesidade/epidemiologia , China/epidemiologia , Fast Foods , Humanos , Características de Residência , Restaurantes , Instituições Acadêmicas
18.
Zhonghua Er Ke Za Zhi ; 57(10): 767-773, 2019 Oct 02.
Artigo em Chinês | MEDLINE | ID: mdl-31594063

RESUMO

Objective: To summarize the clinical characteristics, treatment response and prognostic factors of rhabdomyosarcoma (RMS) in children. Methods: The clinical characteristics such as age at diagnosis, primary tumor site, tumor size, pathological type, clinical stage, and risk grouping of 213 RMS patients (140 males and 73 females) treated in Hematology Oncology Center of Beijing Children's Hospital, Capital Medical University, from May 2006 to June 2018 were analyzed retrospectively. The clinical characteristics, overall survival (OS), event free survival (EFS) and prognostic factors of children treated with the Beijing Children's Hospital-Rhabdomyosarcoma (BCH-RMS) regimen were analyzed. Survival data were analyzed by Kaplan-Meier survival analysis, and single factor analysis was performed by Log-Rank test. Results: The diagnostic age of 213 cases was 48.0 months (ranged 3.0-187.5 months), of which 136 cases (63.8%) were younger than 10 years old. The head and neck region was the most common primary site of tumor (30%, 64 cases), followed by the genitourinary tract (26.8%, 57 cases). Among pathological subtypes, embryonal RMS accounted for 71.4% (152 cases), while alveolar RMS and anaplastic RMS accounted for only 26.8% (57 cases) and 1.9% (4 cases), respectively. According to the Intergroup Rhabdomyosarcoma Study Group (IRS), IRS-Ⅲ and Ⅳ accounted for 85.0% (181 cases) of all RMS patients. In all patients, 9.4% (20 cases) patients were divided in to low-risk group, 52.1% (111 cases) patients in to intermediate -risk group, 25.8% (55 cases) patients in to high-risk group, and 12.7% (27 cases) patients in to the central nervous system invasion group, respectively. All patients with RMS received chemotherapy. The cycles of chemotherapy were 13.5 (ranged 5.0-18.0) for patients without event occurrence, while 14.2 (ranged 3.0-30.0) for patients with event occurrence. Among the 213 patients, 200 patients had surgical operation, of whom 103 patients underwent surgery before chemotherapy and 97 patients at the end of chemotherapy, 21 patients had secondary surgical resection. Radiotherapy was performed in 114 patients. The follow-up time was 23.0 months (ranged 0.5-151.0 months) . There were 98 patients with relapsed or progressed disease and 67 patients with death. The median time to progression was 10 months, of which 67 (68.4%) relapse occurred within 1 year and no recurrence occurred after follow-up for more than 5 years. The 3-year EFS and 5-year EFS were (52±4) % and (48±4) %, while the 3-year OS and 5-year OS were (65±4) % and (64±4) % by survival analysis. The 5-year OS of the low-risk, intermediate-risk, the high-risk were 100%, (74±5) %, (48±8) %, and the 2-year OS of the central nervous system invasion group was (36±11) % (χ(2)=33.52, P<0.01). The 5-year EFS of the low-risk, intermediate-risk, the high-risk were (93±6) %, (51±5) %, (36±7) % and the 2-year EFS of the central nervous system invasion group was (31±10) % (χ(2)=24.73, P<0.01) . Survival factor analysis suggested that the OS of children was correlated with age(χ(2)=4.16, P=0.038), tumor TNM stage (χ(2)=22.02, P=0.001), IRS group (χ(2)=4.49, P<0.01) and the risk group (χ(2)=33.52, P<0.01). Conclusions: This study showed that the median age of newly diagnosed RMS patients was 4 years. The head and neck and the genitourinary tract were the most common primary origin of RMS. The OS was low in single-center RMS children. The median time to recurrence was 10 months, and recurrence was rare 3 years later.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias de Cabeça e Pescoço/diagnóstico , Neoplasias de Cabeça e Pescoço/terapia , Rabdomiossarcoma/diagnóstico , Rabdomiossarcoma/terapia , Neoplasias Urogenitais/diagnóstico , Neoplasias Urogenitais/terapia , Adolescente , Criança , Pré-Escolar , Terapia Combinada , Intervalo Livre de Doença , Feminino , Neoplasias de Cabeça e Pescoço/mortalidade , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Masculino , Recidiva Local de Neoplasia/terapia , Prognóstico , Estudos Retrospectivos , Rabdomiossarcoma/mortalidade , Rabdomiossarcoma/patologia , Rabdomiossarcoma Alveolar , Rabdomiossarcoma Embrionário , Análise de Sobrevida , Neoplasias Urogenitais/mortalidade , Neoplasias Urogenitais/patologia
19.
J Dent ; 90: 103210, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31600535

RESUMO

OBJECTIVES: The present study examined the effects of Na+→K+ ion-exchange on the wear performance of feldspathic veneering porcelain. METHODS: Bar and disk specimens were prepared using IPS classic as the feldspathic veneering porcelain. After ion-exchange by immersion of the specimens in melted KNO3 at two temperatures for different time-periods, the bars were tested for flexural strength and Vickers surface hardness. The disks were paired with zirconia antagonists and tested with a pin-on-disk tribometer with 10 N for 70☓104 wear cycles in artificial saliva. Wear analysis of the porcelain and zirconia was performed using 3D profilometer and analysed with one-way analysis of variance and Tukey's post-hoc pairwise comparison procedures. Worn surfaces were examined with scanning electron microscopy. RESULTS: The feldspathic veneering porcelain exhibited strong time-dependent wear behaviour, with typical running-in and steady wear stages. Ion-exchange treatments at 380 °C and 440 °C both enhanced the mechanical properties, decreased the wear rates of running-in wear and steady wear. The wear performance of porcelain treated by ion-exchange at lower temperature (380 °C) was improved significantly, especially reducing the wear rate of the running-in stage. CONCLUSION: A thicker ion-exchange layer with less stress relaxation may be obtained by ion-exchange at lower exchange temperature for a long processing time. Such a protocol improves the wear performance of the porcelain effectively. CLINICAL SIGNIFICANCE: Restorations with veneering porcelain may fail prematurely due to excessive wear. It important to improve the wear performance of the porcelain. Ion-exchange has the potential to strengthen dental veneering porcelain. Understanding the effect of ion-exchange on the wear performance of porcelain provides insight improving the wear performance of these restorations.

20.
Virology ; 538: 61-70, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31580972

RESUMO

Swine acute diarrhea syndrome coronavirus (SADS-CoV) is a newly identified enteric alphacoronavirus that causes fatal diarrhea in newborn piglets in China. Here, we propagated a virulent strain SADS-CoV/CN/GDWT/2017 in Vero cells for up to 83 passages. Four strains of SADS-CoV/GDWT-P7, -P18, -P48 and -P83 were isolated and characterized. Sequence alignments showed that these four novel strains exhibited 16 nucleotide mutations and resultant 10 amino acid substitutions in open reading frame 1a/1b, spike, NS3a, envelope, membrane and nucleocapsid proteins. Furthermore, a 58-bp deletion in NS7a/7b was found in P48 and P83 strains, which led to the loss of NS7b and 38 amino acid changes of NS7a. Pig infection studies showed that the P7 strain caused typical watery diarrhea, while the P83 strain induced none-to-mild, delayed and transient diarrhea. This is the first report on cell adaption of a virulent SADS-CoV strain, which gives information on the potential virulence determinants of SADS-CoV.

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