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1.
Phys Chem Chem Phys ; 24(13): 7611-7616, 2022 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-35311866

RESUMO

Tunable band gaps make two-dimensional (2D) SnO a promising candidate for a wide variety of applications in optoelectronic devices. In this work, we calculated the structural, electronic, and optical properties of monolayer and mutilayer SnO up to seven layers based on density functional theory. We found that the band gaps of SnO can vary from 0.61 eV to 4.05 eV as the layer number of SnO decreases from seven to one, which is mainly because of the interlayer coupling effect. The interlayer coupling ensures improved carrier transport properties between neighbouring layers, which can benefit the performance of 2D SnO in photovoltaic applications. In particular, a suitable band gap of 1.20 eV for solar cell applications is obtained in trilayer SnO, and the predicted theoretical efficiency of solar cells with trilayer SnO as the active material achieves a high value exceeding 16%, which is relatively high for 2D materials.

2.
Sensors (Basel) ; 21(16)2021 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-34451049

RESUMO

This paper presents a new model for multi-object tracking (MOT) with a transformer. MOT is a spatiotemporal correlation task among interest objects and one of the crucial technologies of multi-unmanned aerial vehicles (Multi-UAV). The transformer is a self-attentional codec architecture that has been successfully used in natural language processing and is emerging in computer vision. This study proposes the Vision Transformer Tracker (ViTT), which uses a transformer encoder as the backbone and takes images directly as input. Compared with convolution networks, it can model global context at every encoder layer from the beginning, which addresses the challenges of occlusion and complex scenarios. The model simultaneously outputs object locations and corresponding appearance embeddings in a shared network through multi-task learning. Our work demonstrates the superiority and effectiveness of transformer-based networks in complex computer vision tasks and paves the way for applying the pure transformer in MOT. We evaluated the proposed model on the MOT16 dataset, achieving 65.7% MOTA, and obtained a competitive result compared with other typical multi-object trackers.

3.
J Prosthodont ; 24(4): 313-21, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25220390

RESUMO

With the techniques of computer-aided design and computer-aided manufacturing (CAD/CAM) being applied in the field of prosthodontics, a concept of intraoral digital impressions was put forward in the early 1980s. It has drawn comprehensive attention from dentists and has been used for dental prosthesis fabrication in a number of cases. This new digital impression technique is expected to bring about absolute digitization to the mode of prosthodontics. A few published articles have indicated that dental prostheses fabricated from intraoral digital impressions have exhibited remarkable advantages over those from conventional impressions in several respects. The present review discusses intraoral digital impression techniques in terms of the following aspects: (1) categories and principles of intraoral digital impression devices currently available; (2) operating characteristics of the devices; and (3) comparison of the manipulation, accuracy, and repeatability between intraoral digital impression and conventional impression.


Assuntos
Desenho Assistido por Computador , Técnica de Moldagem Odontológica , Humanos
4.
J Tradit Chin Med ; 44(2): 373-380, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38504543

RESUMO

OBJECTIVE: To investigate the effectiveness and safety of Jiawei Xiaoyao pill (,JXP) in the treatment of symptoms associated with premenstrual syndrome (PMS). METHODS: A total of 144 regularly menstruating women with PMS were recruited at 8 sites in China from August 2017 to December 2018, and randomized to receive either a JXP or a matching placebo (12 g/d, 6 g twice a day) for 3 menstrual cycles. The primary indicator was the reduced Daily Record of Severity of Problems (DRSP) scores in the luteal phase after 3 months of treatment. The safety outcomes included clinical adverse events (AEs), adverse reactions (ARs), changes in vital signs, and laboratory tests. RESULTS: JXP surpassed the placebo in reducing DRSP scores (psychological/somatic dysfunction) in the luteal phase over 3 menstrual cycles of treatment (PFAS = 0.002, PPPS = 0.001). Additionally, there were no significant differences in the incidence of AEs, severe AEs, withdrawal due to AEs and ARs between the two groups (all P > 0.05), and no clinically significant adverse medical events related to the test drug observed. CONCLUSIONS: JXP was superior to the placebo in relieving the symptoms associated with PMS, which signified that JXP may be effective, safe, and well-tolerated as an alternative therapy.


Assuntos
Medicamentos de Ervas Chinesas , Síndrome Pré-Menstrual , Baço , Feminino , Humanos , Depressão , Temperatura Alta , Síndrome Pré-Menstrual/tratamento farmacológico , Fígado , Método Duplo-Cego
5.
BMC Complement Altern Med ; 13: 186, 2013 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-23870279

RESUMO

BACKGROUND: Total glucosides of paeony (TGP) is a biologically active compound extracted from Paeony root. TGP has been used in rheumatoid arthritis therapy for many years. However, the mechanism by which TGP prevents bone loss has been less explored. METHODS: TGP was orally administered for 3 months to New Zealand rabbits with antigen-induced arthritis (AIA). Digital x-ray knee images and bone mineral density (BMD) measurements of the subchondral knee bone were performed before sacrifice. Chondrocytes were observed using transmission electron microscopy (TEM). Histological analysis and mRNA expression of receptor activator of nuclear factor-B ligand (RANKL) and osteoprotegerin (OPG) were evaluated in joint tissues. RESULTS: The BMD value in TGP rabbits was significantly higher compared with that seen in the AIA model rabbits. In addition, the subchondral bone plate was almost completely preserved by TGP treatment, while there was a decrease in bone plate integrity in AIA rabbits. There was less damage to the chondrocytes of the TGP treated group. Immunohistochemical examination of the TGP group showed that a higher percentage of TGP treated chondrocytes expressed OPG as compared to the chondrocytes isolated from AIA treated animals. In contrast, RANKL expression was significantly decreased in the TGP treated group compared to the AIA group. In support of the immunohistochemistry data, the expression of RANKL mRNA was decreased and OPG mRNA expression was enhanced in the TGP group when compared to that of the AIA model group. CONCLUSION: These results reveal that TGP suppresses juxta-articular osteoporosis and prevents subchondral bone loss. The decreased RANKL and increased OPG expression seen in TGP treated animals could explain how administration of TGP maintains higher BMD.


Assuntos
Artrite Experimental/complicações , Artrite Reumatoide/complicações , Reabsorção Óssea/prevenção & controle , Glucosídeos/uso terapêutico , Osteoporose/prevenção & controle , Paeonia/química , Fitoterapia , Animais , Artrite Experimental/tratamento farmacológico , Artrite Experimental/metabolismo , Artrite Reumatoide/tratamento farmacológico , Artrite Reumatoide/metabolismo , Densidade Óssea , Reabsorção Óssea/metabolismo , Condrócitos/metabolismo , Glucosídeos/farmacologia , Articulação do Joelho/metabolismo , Osteoporose/metabolismo , Osteoprotegerina/genética , Osteoprotegerina/metabolismo , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Raízes de Plantas , Ligante RANK/genética , Ligante RANK/metabolismo , RNA Mensageiro/metabolismo , Coelhos
6.
J Clin Ultrasound ; 41(6): 389-91, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-22573260

RESUMO

Noncompaction of ventricular myocardium (NCVM) is a rare congenital cardiomyopathy characterized by numerous excessively prominent trabeculations and intertrabecular recesses in the myocardium without any other cardiac structural abnormality. Transthoracic echocardiography is the imaging modality of choice for diagnosing NCVM. Although this disease commonly affects the left ventricle, the right ventricle or both ventricles can rarely be affected. We report the case of an 18-year-old male patient with NCVM involving both ventricles.


Assuntos
Miocárdio Ventricular não Compactado Isolado/diagnóstico por imagem , Ultrassonografia Doppler em Cores , Adolescente , Humanos , Masculino
7.
Head Face Med ; 19(1): 3, 2023 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-36747208

RESUMO

OBJECTIVE: This study aimed to evaluate the condylar positional changes following mandibular reconstruction with preservation of the condylar head using Cone-Beam Computed Tomography (CBCT). Also, to assess joint space changes and the overall volumetric space compared to the preoperative status. METHODOLOGY: This prospective study included 30 patients (60 joints) subjected to unilateral mandibular resection and reconstruction with preservation of the condylar head. The Helkimo index and preoperative (T1), two weeks postoperative (T2), and follow-up CBCTs (T3) after at least six months were gathered and processed to evaluate the condylar position and TMJ joint space using Anatomage Invivo 6. A student's t-test and repeated-measures ANOVA statistics were used. A P value of less than 0.05 was considered statistically significant. RESULTS: Thirty patients (14 males, 16 females) with a mean age of 40.01 ± 12.7 years (a range of 18.1-62.9 years) were included. On the tumor side, there were significant variances in the vertical and mediolateral condylar positions between the three-time points (T1, T2, T3). Immediately after the operation, the condyles were significantly displaced in a downward direction at T2, which became larger after the last follow-up period (T3) (p = 0.007). The condylar positions at the anteroposterior direction were relatively stable without significant differences between the three times points (p = 0.915). On the non-tumor side, the condylar positions were relatively stable in the mediolateral and anteroposterior positions. In the tumor side, all of the TMJ spaces were significantly increased in size following the mandibular reconstructions (T2 and T3). However, on the non-tumor side, the anterior, posterior, and medial joint spaces were significantly changed postoperatively. CONCLUSION: After mandibular reconstruction with condylar preservation, the condylar position and volumetric measurement immediately changed noticeably and continued to be a permanent change over time compared to relatively stable condyles on the non-tumor side. According to Helkimo index, patients become adapted to the postoperative changes without significant differences between the two sides.


Assuntos
Reconstrução Mandibular , Tomografia Computadorizada de Feixe Cônico Espiral , Masculino , Feminino , Humanos , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Côndilo Mandibular/diagnóstico por imagem , Côndilo Mandibular/cirurgia , Côndilo Mandibular/anatomia & histologia , Estudos Prospectivos , Mandíbula/diagnóstico por imagem , Mandíbula/cirurgia , Articulação Temporomandibular/diagnóstico por imagem , Articulação Temporomandibular/cirurgia , Tomografia Computadorizada de Feixe Cônico/métodos
8.
Chin Med Sci J ; 27(3): 141-6, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23062635

RESUMO

OBJECTIVE: To assess Chinese surgeon practice of thromboprophylaxis following major orthopedic surgery. METHODS: A questionnaire survey was conducted amongst Chinese orthopedic surgeons. A total of 293 surgeons were surveyed concerning five key aspects of thromboembolic prophylaxis after major orthopedic surgery at the proseminar of Chinese guidelines for prevention of venous thromboembolism (VTE) after major orthopedic surgery in January of 2009. RESULTS: Totally, 208 surgeons (71.0%) responded, successfully completing the questionnaire. Of them, 57.6% respondents selected combined basic, mechanical, and pharmacologic methods for thromboprophylaxis; 51.0% respondents prefer starting prophylaxis 12-24 hours after surgery; 60.3% surgeons would use chemoprophylaxis for 7-10 days; 47.6% respondents prefer VTE prevention based on patients' special conditions and needs upon discharge."Safety" was the most repeated and emphasized factor during VTE prophylaxis. CONCLUSIONS: Multimodal thromboprophylaxis is frequently used after major orthopedic surgery. Half surgeons prefer to start chemoprophylaxis 12-24 hours after surgery. Thromboprophylaxis regimen varies for discharged patients.


Assuntos
Procedimentos Ortopédicos/efeitos adversos , Ortopedia , Complicações Pós-Operatórias/prevenção & controle , Tromboembolia/prevenção & controle , Heparina de Baixo Peso Molecular/uso terapêutico , Humanos , Inquéritos e Questionários
9.
Chin Med Sci J ; 26(4): 221-6, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22218049

RESUMO

OBJECTIVE: To evaluate the efficacy and safety of low molecular weight heparin (LMWH) prophylaxis for venous thromboembolism (VTE) after lumbar decompression surgery. METHODS: Patients at high or the highest risk of VTE who underwent lumbar spine surgery in Peking Union Medical College Hospital from January 2004 to April 2011 were included in the present study. All the patients received a half dose of LMWH 6 hours after surgery followed by a full dose LMWH once per day until discharge. We recorded incidences of deep venous thrombosis (DVT), pulmonary embolism (PE), bleeding complications, and medication side effects. RESULTS: Seventy-eight consecutive patients were eligible and enrolled in this study. The mean hospital stat was 8.5±4.5 days. No symptomatic DVT, PE, or major bleeding events were observed. One patient developed wound ecchymosis, another developed wound bleeding, four had mild hepatic aminotransferase level elevation, and one developed a suspicious allergic reaction. CONCLUSION: LMWH may be applied as an effective and safe prophylaxis for VTE in high-risk patients undergoing lumbar decompression surgery.


Assuntos
Descompressão Cirúrgica/efeitos adversos , Heparina de Baixo Peso Molecular/uso terapêutico , Vértebras Lombares/cirurgia , Tromboembolia Venosa/prevenção & controle , Idoso , Feminino , Heparina de Baixo Peso Molecular/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade
10.
Pan Afr Med J ; 38: 302, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34178220

RESUMO

Acute myocardial infarction (AMI) is a major cause of death in a patient with systemic lupus erythematosus (SLE). Due to their chronic inflammatory state, patient with SLE has an increased risk of developing coronary artery disease. We report a case of a middle-aged woman with an acute myocardial infarction (AMI) caused by a right coronary artery (RCA) stenosis complicated with severe coronary artery spasm. Our patient has a history of long-standing SLE. Clinical expression of coronary artery disease (CAD) in SLE is the result of different pathophysiologic mechanism. From this case, we raise the importance of the clinician to be aware of the diverse pathophysiologic pathways involving a coronary artery in a patient with SLE.


Assuntos
Estenose Coronária/complicações , Vasoespasmo Coronário/complicações , Lúpus Eritematoso Sistêmico/complicações , Infarto do Miocárdio/etiologia , Adulto , Estenose Coronária/fisiopatologia , Vasoespasmo Coronário/fisiopatologia , Feminino , Humanos , Lúpus Eritematoso Sistêmico/fisiopatologia , Infarto do Miocárdio/fisiopatologia
11.
Biomed Opt Express ; 12(4): 1882-1904, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33996205

RESUMO

Catheter-based intravascular optical coherence tomography (IVOCT) is a powerful imaging modality for visualization of atherosclerosis with high resolution. Quantitative characterization of various tissue types by attenuation coefficient (AC) extraction has been proven to be a potentially significant application of OCT attenuation imaging. However, existing methods for AC extraction from OCT suffer from the challenge of variability in complex tissue types in IVOCT pullback data such as healthy vessel wall, mixed atherosclerotic plaques, plaques with a single component and stent struts, etc. This challenge leads to the ineffectiveness in the tissue differentiation by AC representation based on single scattering model of OCT signal. In this paper, we propose a novel method based on multiple scattering model for parametric imaging of optical attenuation by AC retrieval from IVOCT images conventionally acquired during cardiac catheterization. The OCT signal characterized by the AC is physically modeled by Monte Carlo simulation. Then, the pixel-wise AC retrieval is achieved by iteratively minimizing an error function regarding the modeled and measured backscattered signal. This method provides a general scheme for AC extraction from IVOCT without the premise of complete attenuation of the incident light through the imaging depths. Results of computer-simulated and clinical images demonstrate that the method can avoid overestimation at the end of the depth profile in comparison with the approaches based on the depth-resolved (DR) model. The energy error depth and structural similarity are improved by about 30% and 10% respectively compared with DR. It provides a useful way to differentiate and characterize arterial tissue types in IVOCT images.

12.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 27(3): 340-2, 2010 Jun.
Artigo em Zh | MEDLINE | ID: mdl-20533279

RESUMO

OBJECTIVE: To screen and diagnose Down's syndrome during mid-term pregnancy to reduce the number of babies with Down's syndrome. METHODS: With the multi-level of stratified cluster sampling, twenty thousand and eight hundred and three women at 15-20 weeks gestation were screened by maternal serum AFP and beta-hCG using the time resolved fluoroimmunoassay (TRFIA). Then the screened high-risk women were diagnosed by amniocentesis, cell culture and chromosome analyses. The born children were diagnosed by follow-up and peripheral blood chromosome analyses. RESULTS: Six fetuses were diagnosed by serum screening and amniotic fluid chromosome analyses, and 3 born children were diagnosed by follow-up and peripheral blood chromosome analyses. Nine cases of Down's syndrome were detected in total, with the positive prenatal screen rate being 67% (6/9). CONCLUSION: The prenatal screening and diagnosis can reduce the birth of Down's syndrome patients and improve the population quality. However, the diagnosis accuracy still needs to be improved to further reduce the false negative rate and prevent misdiagnosis.


Assuntos
Síndrome de Down/diagnóstico , Diagnóstico Pré-Natal/métodos , Adulto , Gonadotropina Coriônica Humana Subunidade beta/sangue , Aberrações Cromossômicas , Síndrome de Down/sangue , Síndrome de Down/genética , Síndrome de Down/metabolismo , Feminino , Fluorimunoensaio , Humanos , Gravidez , Adulto Jovem , alfa-Fetoproteínas/metabolismo
13.
Amyloid ; 27(1): 36-44, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31635489

RESUMO

Background: Amyloid light chain (AL) amyloidosis is characterized by tissue deposition of amyloid fibres derived from immunoglobulin that can lead to irreversible organ damage. Information about genomic profiles of AL amyloidosis is lacking.Methods: In this study, we adopted a two-step strategy to investigate the mutational profile of AL amyloidosis bone marrow plasma cells (PCs) and their clinical implications. In step one, whole-exome sequencing was performed in bone marrow PCs and paired with normal tissue from 10 AL amyloidosis patients, by which we identified 10 significantly mutated genes (SMGs). In step two, we constituted a targeted gene sequencing (TGS) panel covering the frequently mutated genes identified in step one, genes reported in prior AL amyloidosis studies, and known cancer driver mutations. Then, we analysed an expanded cohort of AL amyloidosis patients (N = 48) with this panel comprising 98 genes.Results: Four recurrent mutations were identified by TGS and verified by Sanger sequencing: ASB15 (c. 844 C > T), ASCC3 (c. 1595 A > G), HIST1H1E (c. 311 C > T) and KRAS (c. 35 G > A), among which the first three mutations were associated with inferior overall survival (OS). Additionally, we found that the number of mutations identified by the TGS panel of 98 genes could be a prognostic predictor for OS.Conclusions: In summary, we revealed genomic profiling in AL amyloidosis and found mutation profiles associated with OS.


Assuntos
DNA Helicases/genética , Histonas/genética , Amiloidose de Cadeia Leve de Imunoglobulina , Mutação , Proteínas/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Adulto , Idoso , Análise Mutacional de DNA , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Amiloidose de Cadeia Leve de Imunoglobulina/tratamento farmacológico , Amiloidose de Cadeia Leve de Imunoglobulina/genética , Amiloidose de Cadeia Leve de Imunoglobulina/mortalidade , Masculino , Pessoa de Meia-Idade , Taxa de Sobrevida
14.
Zhonghua Nan Ke Xue ; 15(9): 855-60, 2009 Sep.
Artigo em Zh | MEDLINE | ID: mdl-19947573

RESUMO

OBJECTIVE: Shen Yan Ling Tablet is an innovative compound of traditional Chinese medicine, scientifically prepared with Tripterygium wilfordii, Radix Astragali, and others, with precise efficacy on renal diseases and reduced adverse effects of Tripterygium wilfordii. Based on the Guiding Principles for New Drug Toxicity Research Before Clinical Application, we investigated the long-term toxicity of Shen Yan Ling Tablet and its effect on the reproductive function in rats. METHODS: According to the clinical therapeutic dose and the results of the acute toxicity test of Shen Yan Ling Tablet, we equally divided 80 rats (males and females half-and-half) into a low-dose (1.25 g/kg body wt), a medium-dose (2.50 g/kg body wt), a high-dose (5.00 g/kg body wt) and a control group. After a 3-month medication, we conducted standardized long-term toxicity tests and observed the effects of Shen Yan Ling on the serum sexual hormones and epididymal sperm count. RESULTS: After 3 months of treatment with Shen Yan Ling, no death occurred, the general status remained unchanged, and the parameters of blood cytology and biochemistry fluctuated within the normal range, without any significant changes (P > 0.05). Some blood parameters, RBC, WBC, HGB, AST and TBIL, showed statistic changes (P < 0.05), but with no clinical significance. There were no significant differences in the mass coefficients of the main organs between the medication and control groups. The high-dose group exhibited slight hepatic and pulmonary pathological changes and significantly reduced sperm counts in the epididymis, but no significant changes in serum sexual hormones (P < 0.05). CONCLUSION: Three-month medication of Shen Yan Ling at 1.25 - 5.00 g/kg produced no significant accumulated toxicity on rats, but it had a negative effect on their reproductive function at a higher dose of > or = 5.00 g/kg.


Assuntos
Epididimo/efeitos dos fármacos , Extratos Vegetais/toxicidade , Testes de Toxicidade Aguda , Tripterygium , Animais , Medicamentos de Ervas Chinesas/toxicidade , Feminino , Masculino , Nefrite/tratamento farmacológico , Tamanho do Órgão , Fitoterapia , Ratos , Ratos Sprague-Dawley , Espermatozoides/efeitos dos fármacos , Comprimidos
15.
World Neurosurg ; 129: e494-e501, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31150853

RESUMO

OBJECTIVE: Hemorrhage in the basal ganglia is a common type of intracerebral hemorrhage and has high mortality and poor prognosis. In our study, we aimed to evaluate surgical outcomes and functional recovery after evacuation of hematoma using either craniotomy or endoscopy. METHODS: We analyzed retrospective data from 58 patients with basal ganglia hemorrhage who were treated with hematoma evacuation using either craniotomy or endoscopy. Magnetic resonance imaging and a navigation system were used for calculating hematoma volume and for navigation during surgery. Clinical information and surgical outcomes were recorded. At 6-month follow-up, the recovery of neurologic function and the results of the Aphasia Battery of Chinese test were assessed. RESULTS: The endoscopy group showed lower intraoperative blood loss (75.36 ± 45.56 vs. 462.67 ± 120.08 mL, P < 0.001), shorter operation time (1.59 ± 0.30 vs. 4.17 ± 0.86 hours, P < 0.001), and a higher hematoma clearance rate (0.93% ± 0.05% vs. 0.88% ± 0.13%, P = 0.04) than the craniotomy group, respectively. No significant differences in mortality were identified, but a trend toward lower mortality in the endoscopy group was apparent (7.14% in the endoscopy group vs. 16.67% in the craniotomy group, P = 0.43). Assessment of neurologic recovery indicated significant differences in the modified Rankin Scale grades between the 2 groups (χ2 = 4.381, P = 0.036). Listening comprehension and speaking ability were also better in the endoscopy group than the craniotomy group (χ2 = 4.693, P = 0.03). CONCLUSIONS: Evacuation by endoscopy had better surgical outcomes, recovery of neurologic function, and aphasia recovery than evacuation by craniotomy. It appears that endoscopy is the surgical treatment of choice for middle-aged and elderly patients with a basal ganglia hemorrhage volume of >35 mL.


Assuntos
Hemorragia dos Gânglios da Base/cirurgia , Gânglios da Base/cirurgia , Craniotomia/métodos , Neuroendoscopia/métodos , Recuperação de Função Fisiológica/fisiologia , Idoso , Gânglios da Base/diagnóstico por imagem , Hemorragia dos Gânglios da Base/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
16.
IEEE Trans Cybern ; 47(8): 2312-2320, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27925601

RESUMO

This paper addresses the stability of networked control systems with aperiodic sampling and time-varying network-induced delay. The sampling intervals are assumed to vary within a known interval. The transmission delay is assumed to belong to a given interval. The closed-loop system is first converted to a discrete-time system with multiple time-varying delays and norm-bounded uncertainties resulting from the variation of the sampling intervals. And then, it is transformed into a delay-free system being form of an interconnection of two subsystems. By utilizing scaled small gain theorem, an asymptotic stability criterion for the closed-loop system is proposed in terms of linear matrix inequality. Finally, numerical examples demonstrate the effectiveness of the proposed method and its advantages over existing methods.

17.
J Clin Endocrinol Metab ; 91(2): 460-70, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16278260

RESUMO

CONTEXT: Previous male contraceptive studies showed that progestins enhance spermatogenesis suppression by androgens in men. OBJECTIVE: We compared the efficacy of spermatogenesis suppression by the combination of levonorgestrel (LNG) with testosterone (T) implants to that by T implants alone in two different ethnic groups. DESIGN: This was a randomized trial performed in two centers with two treatment groups. SETTINGS: The study was performed at the Academic Medical Center in the United States and the Research Institute in China. PARTICIPANTS: Forty non-Chinese and 40 Chinese healthy male volunteers were studied. INTERVENTIONS: Subjects were randomized to receive four LNG implants together with four T implants (inserted on d 1 and wk 15-18) vs. T implants alone for 30 wk. MAIN OUTCOME MEASURES: The primary end point compared the efficiency of suppression to severe oligozoospermia (1 x 10(6)/ml) by LNG plus T implants vs. that by T implants alone. The secondary end point examined differences in spermatogenesis suppression between Chinese and non-Chinese subjects. RESULTS: LNG plus T implants caused more suppression of spermatogenesis to severe oligozoospermia during the treatment period than T implants alone at both sites (P < 0.02). In Chinese men, severe oligozoospermia was achieved in more than 90% of the men in both treatment groups. Suppression to severe oligozoospermia was less in the non-Chinese men (59%) after T alone (P < 0.020); this difference disappeared with combined treatment (89%). T implant extrusion occurred in six men. Acne and increased hemoglobin were the most common adverse events. CONCLUSION: T implants resulted in more pronounced spermatogenesis suppression in Chinese men. Addition of LNG implants to T implants enhanced the suppression of spermatogenesis in the treatment period in both Chinese and non-Chinese men.


Assuntos
Anticoncepção/métodos , Levanogestrel/farmacologia , Espermatogênese/efeitos dos fármacos , Testosterona/farmacologia , Adulto , China/etnologia , Implantes de Medicamento/administração & dosagem , Implantes de Medicamento/farmacologia , Sinergismo Farmacológico , Hormônio Foliculoestimulante/sangue , Humanos , Levanogestrel/administração & dosagem , Hormônio Luteinizante/sangue , Masculino , Pessoa de Meia-Idade , Oligospermia/induzido quimicamente , Globulina de Ligação a Hormônio Sexual/metabolismo , Contagem de Espermatozoides , Testosterona/administração & dosagem , Testosterona/sangue , Estados Unidos
18.
Zhonghua Nan Ke Xue ; 11(6): 438-41, 2005 Jun.
Artigo em Zh | MEDLINE | ID: mdl-15999489

RESUMO

OBJECTIVE: To understand the state of health of the middle-aged and old males in Jiangsu Province. METHODS: A total number of 3 551 middle-aged and old males aged 46 approximately 69 years were randomly selected from 13 counties of Jiangsu Province. All of them received physical examinations, including laboratory tests of liver and kidney function, sugar and cholesterols, radioimmunoassay of testosterone and free testosterone levels in the serum, and B-ultrasonic examination of the prostate volume and remaining urine. They also underwent inquiries according to the International Index of Erectile Function (IIEF-5) and the questionnaire for PADAM (partial androgen deficiency of the aging male). RESULTS: The prostate volume differed significantly (P < 0.05), while the testosterone level showed no significant difference in different age groups (P > 0.05). The level of the free testosterone in the serum descended with the increase of age. The incidence of ED and PADAM was also correlated with the increase of age. CONCLUSION: In the old and middle-aged population of males, with the increase of age, sexual function decreases, the prostate volume enlarges, and the incidence of ED and PADAM obviously increases (P < 0.001).


Assuntos
Disfunção Erétil/epidemiologia , Inquéritos Epidemiológicos , Próstata/diagnóstico por imagem , Idoso , Androgênios/deficiência , China/epidemiologia , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Testosterona/sangue , Ultrassonografia
19.
Zhonghua Nan Ke Xue ; 11(1): 38-41, 2005 Jan.
Artigo em Zh | MEDLINE | ID: mdl-15704680

RESUMO

OBJECTIVE: To investigate whether 5alpha-reductase inhibitor and dihydrotestosterone (DHT) play a role in spermatogenesis in male rats. METHODS: Thirty-two male rats were divided into 4 groups (Groups C, T, F and FT). Group C received plant oil injection and oral starch perfusion, Group T testosterone undecanoate (TU, 20 mg/kg) injection and oral starch perfusion, Group F plant oil injection and oral Finasteride perfusion, and Group FT TU (20 mg/kg) injection and oral Finasteride perfusion. Data on serum T and DHT, sperm count, sperm mobility and reproductive function were collected and analysed. RESULTS: (1) 5alpha-reductase inhibitor, Finasteride and TU reduced the weight of the testis and epididymis in the experiment groups compared with the negative control (Group C), but TU increased the weight of the prostate while Finasteride decreased it compared with the positive control (Group T). TU combined with Finasteride could counteract the effect of the weight increase of the prostate, but not that of the testis. (2) Finasteride, or Finasteride combined with TU, reduced the DHT but increased the testosterone level in comparison with the control group. (3) Both Finasteride and TU could inhibit epididymal sperm count and reproductive function compared with the control, but the effect was less significant in Group FT than in Group F. CONCLUSION: High dosages of 5alpha-reductase inhibitor, Finasteride, can suppress male reproductive function, but the inhibiting effect could be counteracted by administration of 5alpha-reductase inhibitor along with TU.


Assuntos
Colestenona 5 alfa-Redutase/antagonistas & inibidores , Di-Hidrotestosterona/farmacologia , Finasterida/farmacologia , Espermatogênese/efeitos dos fármacos , Testosterona/análogos & derivados , Animais , Relação Dose-Resposta a Droga , Masculino , Tamanho do Órgão , Próstata/efeitos dos fármacos , Próstata/patologia , Ratos , Ratos Sprague-Dawley , Testículo/efeitos dos fármacos , Testículo/patologia , Testosterona/farmacologia
20.
Zhonghua Nan Ke Xue ; 11(9): 652-4, 2005 Sep.
Artigo em Zh | MEDLINE | ID: mdl-16209201

RESUMO

OBJECTIVE: To identify the role of 5alpha-reductase in the spermatogenesis of male rats by studying the effect of two 5alpha-reductase inhibitors, Epristeride and Finasteride, on the spermatogenesis in male Sprague-Dawley (SD) rats. METHODS: Changes in the weight of the testis, serum testosterone and dihydrotestosterone levels, epididymal sperm count, and reproductive function were observed and analyzed after the two 5alpha-reductase inhibitors were administered to male SD rats orally. RESULTS: The experiment showed that in comparison with control animals, both the two 5alpha-reductase inhibitors: 1. suppressed the development of the prostate and reduced the weight of the testis in the experimental groups (P < 0.05); 2. decreased the serum level of dihydrotestosterone and enhanced testosterone; 3. inhibited epididymal sperm count and productive function. CONCLUSION: High dosages of the 5alpha-reductase inhibitor, Epristeride, can suppress the development of the prostate and reduce the weight of the testis, decrease dihydrotestosterone, and inhibit spermatogenesis and productive function in male rats.


Assuntos
Inibidores de 5-alfa Redutase , Androstadienos/farmacologia , Espermatogênese/efeitos dos fármacos , Animais , Relação Dose-Resposta a Droga , Finasterida/farmacologia , Masculino , Ratos , Ratos Sprague-Dawley
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