期刊文献+
共找到8,014篇文章
< 1 2 250 >
每页显示 20 50 100
Alleviating effects of melatonin on oxidative changes in the testes and pituitary glands evoked by subacute chlorpyrifos administration in Wistar rats 被引量:6
1
作者 Angela J Umosen Suleiman F Ambali +2 位作者 Joseph O Ayo Bisala Mohammed Chidiebere Uchendu 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2012年第8期645-650,共6页
Objective:To evaluate the alleviating effects of melatonin on oxidative changes in the testes and pituitary gland induced by subacute chlopyrifos(CPF) exposure in rats.Methods:Forty adult male Wistar rats divided in... Objective:To evaluate the alleviating effects of melatonin on oxidative changes in the testes and pituitary gland induced by subacute chlopyrifos(CPF) exposure in rats.Methods:Forty adult male Wistar rats divided into 4 groups of 10 animals were used for the study.Croup I received soya oil(2 mL/kg) while group II was administered with melatonin(0.5 mg/kg).Group III was administered CPF only(8.5 mg/kg <sup> </sup>l/10th of the LD<sub>50</sub>) while group Ⅳ was pretreated with melatonin(0.5 mg/kg) and then exposed to CPF(8.5 mg/kg),10 min later.The regimens were administered by gavage once daily for a period of 28 d.At the end of the exposure period, the rats were sacrificed and the testicular tissues and pituitary glands were evaluated for the malonaldehyde(MDA) concentration and activities of superoxide dismutase(SOD) and catalase(CAT).Results:CPF increased MDA concentrations and reduced the activities of SOD and CAT in the testes and pituitary gland.Melatonin pretreatment reduced the testicular and pituitary MDA concentrations and improves the SOD and CAT activities.Conclusions:the study showed that subacute CPF-induced oxidative stress in the testes and pituitary glands were alleviated by melatonin due to its antioxidant property. 展开更多
关键词 CHLORPYRIFOS OXIDATIVE stress testeS Pituitary GLANDS Alleviation MELATONIN
下载PDF
Expression of toxin-related human mono-ADP-ribosyltransferase 3 in human testes 被引量:5
2
作者 Maik Friedrich Andreas Grahnert +3 位作者 Uwe Paasch Andrea Tannapfel Friedrich Koch-Nolte Sunna Hauschildt 《Asian Journal of Andrology》 SCIE CAS CSCD 2006年第3期281-287,共7页
Aim: To investigate wether the corresponding protein of mono-ADP-ribosyltransferase 3 (ART3) mRNA is expressed in human testes and, if so, whether the expression is cell type-specific. Methods: ART3 mRNA was deter... Aim: To investigate wether the corresponding protein of mono-ADP-ribosyltransferase 3 (ART3) mRNA is expressed in human testes and, if so, whether the expression is cell type-specific. Methods: ART3 mRNA was determined in human testes and sperm by reverse transcription-polymerase chain reaction (RT-PCR). The glycosylphosphatidylinositol linkage of ART3 was shown by treating ART3-transfected HEK-293-T cells with phospholipase C. Fluorescent activated cell sorter (FACS)-analyses were used to detect ART3 on mature spermatozoa and immunohistological studies to detect the protein in testes. Results: ART3 protein was shown to be present in testes. It was found on spermatocytes only. It was absent from spermatogonia, spermatids and spermatozoa. The absence of ART3 from spermatozoa was confirmed by FACS-analysis. ART3 protein was detected neither within a seminoma nor on Leydig cells. Conclusion: Here we show for the first time that ART3 protein is expressed in testes in particular on spermatocytes, indicating that ART3 exerts a specific function only required at a particular stage of spermatogenesis. 展开更多
关键词 mono-ADP-ribosyltransferase 3 testeS human spermatocyte SPERMATOGENESIS
下载PDF
Asymmetry of Testes in Guenther's Frog,Hylarana guentheri(Anuar:Ranidae) 被引量:3
3
作者 Yanhong LIU Wenbo LIAO +2 位作者 Caiquan ZHOU Zhiping MI Min MAO 《Asian Herpetological Research》 SCIE 2011年第4期234-239,共6页
Testes size in most animals commonly shows directional asymmetry. In birds, the left testis mass is usually larger than the right one, but the reports on the testes asymmetry in anurans are very few. Moller (1994) h... Testes size in most animals commonly shows directional asymmetry. In birds, the left testis mass is usually larger than the right one, but the reports on the testes asymmetry in anurans are very few. Moller (1994) hypothesized that the right testis serves a compensatory role and increases in size when the left one is defective, and further suggested that testes asymmetry may be a reliable indicator of individual body condition. In this paper, we tested the compensation hypothesis in the Guenther's frog, Hylarana guentheri. From 60 sampled males, we found that there was a significant directional asymmetry in testes mass, with the left testis size being significantly correlated with relative testes asymmetry, providing evidence that the right testis had a compensatory function. However, testes mass and asymmetry were not correlated with body condition. Hence, we found no evidence that testes asymmetry in the Guenther's frog reflected male condition, and male age was also not related to testes mass or asymmetry. 展开更多
关键词 directional testes asymmetry compensation hypothesis body condition Hylarana guentheri
下载PDF
Inhibitory Effect of Aqueous Extract of Moringa oleifera and Newbuoldia laevis Leaves on Ferrous Sulphate and Sodium Nitroprusside Induced Oxidative Stress in Rat’s Testes in Vitro 被引量:2
4
作者 Seun F. Akomolafe Ganiyu Oboh +2 位作者 Afolabi A. Akindahunsi Ayodele J. Akinyemi Olusola Adeyanju 《Open Journal of Medicinal Chemistry》 2012年第4期119-128,共10页
Oxidative stress has been identified as one of the factors that affects fertility status. Therefore, this study sought to investigate the inhibitory effect of aqueous extract of Moringa oleifera and Newbuoldia laevis ... Oxidative stress has been identified as one of the factors that affects fertility status. Therefore, this study sought to investigate the inhibitory effect of aqueous extract of Moringa oleifera and Newbuoldia laevis leaves on FeSO4 and Sodium Nitroprusside (SNP) induced lipid peroxidation in rat testes in vitro. Incubation of the testes tissue homogenate in the presence of FeSO4 and SNP caused a significant increase in the malondialdehyde (MDA) contents of the testes. The aqueous extract from both Moringa oleifera and Newbuoldia laevis leaves caused a significant decrease in the MDA contents of the testes in a dose-dependent manner. However, aqueous extract from Moringa oleifera leaf (EC50 = 0.29 mg/ml) had a significant (P2+ induced lipid peroxidation in the rat testes homogenate than that of Newbuoldia laevis leaf extract (EC50 = 0.58 mg/ml);while there was no significant (P2+ chelating and reducing power. Therefore, these plants have potential to prevent oxidative stress in testes and improve fertility outcomes. 展开更多
关键词 LIPID PEROXIDATION MALONDIALDEHYDE Antioxidant Activity testeS
下载PDF
Induction of Apoptosis in the Immature Mouse Testes by a Mixture of Melamine and Cyanuric Acid 被引量:1
5
作者 YOU Hua ZHU Jin-feng +9 位作者 SHE Rui-ping CHANG Ling-ling SHI Rui-han DING Ye CHI Li-juan LIU Bin YUE Zhuo TIAN Ji-jing MAO Jing-jing SU Li-fang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2012年第12期2058-2066,共9页
The toxicity of melamine has attracted much attention since the recent outbreaks of renal injury in pets and infants. Previous studies indicated that melamine by itself had low toxicity, whereas a mixture of melamine ... The toxicity of melamine has attracted much attention since the recent outbreaks of renal injury in pets and infants. Previous studies indicated that melamine by itself had low toxicity, whereas a mixture of melamine and cyanuric acid (M+CA) could cause serious renal damage. At present, most researches on the toxicity of M+CA are focused on the kidney. However, little is known about the adverse effects of this mixture on the reproductive system. In the present study, the toxicity of M+CA to testes was investigated. Immature male mice were orally dosed with 0, 0.6, 3, and 15 mg kg-1 d-1 of a 1:1 M+CA for 28 d. Pathological changes occurred in germ cells, such as loose arrangement, reduced numbers and karyopyknosis, indicating that this mixture was toxic to spermatogenesis. Compared with the control group, the TUNEL- positive germ cells increased significantly and the ratio of Bcl-2 to Bax, total antioxidant capacity and superoxide dismutase activity decreased significantly in the 3 and 15 mg kg-1 d- M+CA treated group, while the activities of caspase-3, caspase- 8 and caspase-9 remained unchanged. The results suggest that M+CA can induce apoptosis in the mice testes. The downregulation of Bcl-2/Bax and oxidative stress may play a pivotal role in the induction of apoptosis by M+CA in mice testes. 展开更多
关键词 melamine/cyanuric acid mixture testeS injury caspase-independent apoptosis
下载PDF
Design and verification of portable direct shear tester with application to remolded colluvium geomaterials
6
作者 K.J.Shou Y.W.Lin 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE 2012年第4期326-332,共7页
The mechanical properties of colluvium strongly govern the stability of colluvial slopes, and they arc essential for the related analysis and design. Nevertheless, their measurement is not easy on account of heterogen... The mechanical properties of colluvium strongly govern the stability of colluvial slopes, and they arc essential for the related analysis and design. Nevertheless, their measurement is not easy on account of heterogeneity in property and difficulty of sampling. This study attempted to evaluate the shear strength of remolded colluvium by means of a simple direct shear test in the field. A portable direct shear tester was designed to overcome the inconvenience and expensiveness of the conventional large-scale in-situ direct shear test. It can be easily assembled and applied for the silnplc field direct shear test. For calibration, the results of the portable direct shear tester were compared with the results of the laboratory direct shear tester for four different types of soil samples, i.e. standard sand, slate debris, arenaceous shale debris and mixture of gravel and sand. Correlation formulas were established based on the calibration, enabling the portable direct shear tester to measure and estimate the shear strength of remoldcd colluvium in field. This study primarily focuses on the colluvium in Central Taiwan, including the lateritic Dadu Terrace and the arcnaceous shale of Taiping-Wufcng mounts. The portable direct shear tester was applied to sites selected in these areas, and the results were furthcr analyzed and discussed. 展开更多
关键词 direct shear test portable direct shear tester simple field direct shear test colluvial slope
下载PDF
Growth and Development of Testes in Domesticated and Hybrid(wild × domesticated)Yak Bulls
7
作者 Yan Ping Pan Heping Zhi Dejuan 《中国草食动物》 2005年第z2期26-30,共5页
Testicular tissue was studied in domesticated yak and in wild yak × domesticated yak(F1 and F2)bulls at 6,12,18 and 24 months of age by stereology for quautitative histology and by comparative studies on the lact... Testicular tissue was studied in domesticated yak and in wild yak × domesticated yak(F1 and F2)bulls at 6,12,18 and 24 months of age by stereology for quautitative histology and by comparative studies on the lactate dehydrogenase(LDH)isoenzyme spectrum, LDH activity and the percentage content of LDH isoenzymes in testes. The results indicated that all three types of yak were similar in both the characteristics of ultrastructure of testicular tissue and the degree of germ cell development. The process of spermatogenesis was initiated and sperm were produced for the first time at the age of 12months in all three yak types. All yak types exhibited similar age-related, increases in weight of testes,volume density of both the seminiferous tubules and seminiferous epithelium and height of seminiferous epithelium but all these indexes were slightly affected by season. The number of LDH isoenzyme bands after electrophoresis varied with age as follows: four bands were present at 6 months of age, five bands at 12 and 18 months and six bands at 24 months of age. The sixth band was LDH -x ,which appeared between the LDH4 and LDH5 band. These results indicated that yak bulls reach sexual maturity at 24months of age and that puberty is not affected by infusion of wild strains. 展开更多
关键词 HISTOLOGY LACTATE dehydragenase testeS ULTRASTRUCTURE Yaks.
下载PDF
Histomorphometry of the Testes, Epididymides, and Spermatozoa of Four Indigenous Breeds of Bulls in Ibadan, Nigeria
8
作者 Ayodeji Ayotunde Oni Matthew Olugbenga Oyeyemi Joseph Atawalna 《Open Journal of Veterinary Medicine》 2021年第9期299-306,共8页
Forty testicles were used to carry out histomorphometry study on the testes, epididymides and spermatozoa of four indigenous breeds of bull found in Ibadan (Red Bororo (RB), Sokoto Gudali (SG), White Fulani (WF) and D... Forty testicles were used to carry out histomorphometry study on the testes, epididymides and spermatozoa of four indigenous breeds of bull found in Ibadan (Red Bororo (RB), Sokoto Gudali (SG), White Fulani (WF) and Dhali (DL)<span style="font-family:;" "="">)</span><span style="font-family:;" "="">. The testicles were harvested immediately after the slaughter at the Bodija abattoir and transported to the laboratory in an insulated flask containing warm water at 37<span style="color:#4F4F4F;font-family:-apple-system, " font-size:16px;white-space:normal;background-color:#ffffff;"="">°</span>C within 30 minutes. In the laboratory, the samples were dissected and histological sections of the right testis, right and left caudal epididymides taken from two bulls in each group. The tissues were fixed in Bouin’s fluid. They were processed in an automatic tissue processor, embedded in paraffin wax using the embedding system (Leica EG 1160) and sectioned with microtome at 4 microns. The sections were then stained by <span>Haematoxylin and Eosin method and mounted and examined under a microscope. There was no significant difference between breed and seminiferous</span> tubular diameter (STD) and testicular germinal height (TGEH). The mean STD ranged from 223.00 ± 28.35 to 316.00 ± 37.70 μm, while the TGEH ranged from 81.60 ± 10.05 to 89.80 ± 4.83 μm. The mean epididymal tubular diameters (ETD) and epididymal lumen diameters (ELD) had the highest value of 378.00 ± 10.95 and 298.20 ± 26.0489 μm in DL and lowest of 373.80 ± 37.70 and 278.10 ± 27.71 μm in RB, respectively. The mean epididymal germinal epithelia heights (EGEH) were highest (61.20 ± 5.70 μm) in WF and lowest (39.80 ± 0.86 μm) in RB. The mean sperm head length (SHL), sperm midpiece length (SMPL), sperm tail length (STL) and sperm total length (TL) had the highest values of 5.90 ± 0.10, 8.80 ± 0.25, 24.20 ± 2.59 and 38.90 ± 2.94 μm, respectively in SG. SHL and SMPL were lowest in DL bulls (5.00 ± 0.00 and 6.30 ± 0.20 μm), while STL and TL were lowest (18.90 ± 0.24 and 31.30 ± 0.85 μm). The results of this study provide baseline data on the histomorphometry of the testes and epididymides and spermatozoa of some indigenous bulls.</span> 展开更多
关键词 HISTOMORPHOMETRY testeS EPIDIDYMIS SPERMATOZOA Indigenous Bull
下载PDF
Ultrastructural Alterations in Testes from Rats Treated with Cysteine
9
作者 A.S.BERNACCHI E.C.DEFERREYRA +1 位作者 C.R.DECASTRO J.A.CASTRO 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 1993年第2期172-178,共7页
Cysteinc administration in relatively large doses has been repetitively employed as preventive agent against chemically induced cell injury or as radioprotector. In this work we report that administration of a dose st... Cysteinc administration in relatively large doses has been repetitively employed as preventive agent against chemically induced cell injury or as radioprotector. In this work we report that administration of a dose standard for those purposes (1.9gr/kg, po in water) causes significant ultrastructurally evident alterations in testcs at 24h. Damage involves Scrtoli cells and spermatids. Alterations found in the former include dilatation of nuclear membrane and of the smooth (SER) and rough endoplasmic reliculum (RER) and detachment of ribosomes from RER. Cytoplasm appeared more sparse and electron lucent than in controls and contained more lipid droplets and lysosomcs. Mitochondria exhibited alterations in shape and size.Damage in spermatids consisted of the appearance of irregular shape of the nucleus and alterations in their acrosomal caps. There was no histochemical evidence for either calcium accumulation or lipid peroxidation occurrence in testes of cysteine-trcated animals. Results indicate that the large doses of cysteine employed in prevention of radiation or chemical effects is able to cause injury to Sertoli cells of the testes. Damage observed does not reach irreversible stages but may be sufficient to lead to production of abnormal spermatids. 展开更多
关键词 Ultrastructural Alterations in testes from Rats Treated with Cysteine
下载PDF
The Danger within:Covid-19 Affinity for ACE2 Receptors in Adipose Tissue and Testes.The Protective Effects of Estradiol,Fitness,and Weight Management
10
作者 Xanya Sofra 《Journal of Endocrinology Research》 2020年第1期1-14,共14页
The imminent danger of the Covid-19 pandemic has accelerated research in pharmaceuticals that either target the viral Spike proteins fusion with ACE2 receptors,or the infectious RNA replication that often overwhelms i... The imminent danger of the Covid-19 pandemic has accelerated research in pharmaceuticals that either target the viral Spike proteins fusion with ACE2 receptors,or the infectious RNA replication that often overwhelms immune defences.The scope of this review was to elucidate the main human vulnerabilities to Covid-19,including the accumulation of ACE2 receptors in testes,adipose tissue,thyroid,heart and kidneys that escalate viral affinity in males,the aged,and certain medical conditions,including diabetes,CVD,and pulmonary diseases.Pre-existing inflammation inherent in obesity may exacerbate the“cytokine storm,”a rampaging immune reaction during the course of Covid-19 that is deleterious to the host.We examined the molecular dynamics illustrating the action of new therapeutics necessary for Covid-19 patients;the estradiol advantage hypothesis;alternative therapies including hormone replacement procedures and mesenchymal stem cells;plus preventive and protective interventions.The current perspective also explored the primary components of dysregulated health predisposing individuals to Covid-19,including hormonal imbalance,increased lipids and lipoproteins,thyroid dysfunction,degraded fitness,and age-related testosterone decline accompanied by cortisol increase that provokes stress eating behaviours and weight accumulation.Obesity increases the probability of Covid-19 infection due to its abundance of ACE2 receptors;while physical activity may decrease Covid-19 vulnerability,by reducing fat and increasing muscle mass that manifests a relatively inhibited ACE2 expression.Several weight management solutions feature lasers and radiofrequency which diminish subcutaneous adiposity but do not enhance fitness.A data metanalysis of seven recently published clinical studies on 95 obese individuals,73 males and 22 females with an average BMI of 30.9,demonstrated visceral fat reduction combined with increased skeletal muscle mass.It also revealed a statistically significant decrease in BMI,lipids,lipoproteins,inflammation and toxicity as measured by CRP,Creatinine and Bilirubin respectively,juxtaposed by optimally healthier levels of Cortisol,Testosterone,Free T3,IGF-1,Insulin,and the appetite controlling hormones Leptin and Ghrelin. 展开更多
关键词 Visceral Adipose Tissue ACE2 testeS Covid-19 ESTRADIOL FITNESS Weight management Leptin Free T3 Testosterone BMI BMR VLDL Triglycerides HDL Creatinine Bilirubin Ghrelin Insulin IGF-1 Cortisol CRP Diabetes PREDIABETES HYPERPHAGIA
下载PDF
Biological Effects of Deer Semen on Development of Testes in Mice 被引量:1
11
作者 Lian Zhengxing, Li Wu (Northeast Agricultural University, Harbin 150030, PRC) 《Journal of Northeast Agricultural University(English Edition)》 CAS 1997年第1期52-54,共3页
immature male mice were selected in the experiment to assess the effects of Deer semen on the development of testes. 20 mice were fed with 0.05 mL semen·d -1 for 15 days and the rest fed with the same volume... immature male mice were selected in the experiment to assess the effects of Deer semen on the development of testes. 20 mice were fed with 0.05 mL semen·d -1 for 15 days and the rest fed with the same volume of albumeh for the same period as controls. The relative weight of testis to body weight was higher in treated group than that in the control (P<0.05), so was the volume of testis (P<0.05). The density of testis was lower in treated group than in the control (P<0.05). Eighty percent of mice in the treated group showed the appearance of tubule cavity and spermatozoa in the testis, but only about 20% in the control. It was concluded that the Deer semen had improvement effects on the development of testes and sexual maturity of mice. 展开更多
关键词 SEMEN testes deer MOUSE
全文增补中
Tried and Tested Online
12
作者 Hou Weili 《ChinAfrica》 2017年第10期22-23,共2页
THE name Zhen Huan has once again become a household name across China, On August 18, 2017, the author of the popular novel featuring Zhen's life in the imperial court in the Qing Dynasty (1644-1911), now also a hi... THE name Zhen Huan has once again become a household name across China, On August 18, 2017, the author of the popular novel featuring Zhen's life in the imperial court in the Qing Dynasty (1644-1911), now also a hit TV series, filed the first case tried by the first online court, Hangzhou Court of the Internet, in China - and the world, 展开更多
关键词 Tried and tested Online
下载PDF
Variation of the mechanical properties of tungsten heavy alloys tested at different temperatures 被引量:4
13
作者 S.H.Islam 《Rare Metals》 SCIE EI CAS CSCD 2011年第4期392-395,共4页
The high-temperature mechanical properties of 95W-3.5Ni-1.5Fe and 95W-4.5Ni-0.5Co alloys were investigated in the temperature range of room temperature to1100℃. The yield strength and tensile strengths declined gradu... The high-temperature mechanical properties of 95W-3.5Ni-1.5Fe and 95W-4.5Ni-0.5Co alloys were investigated in the temperature range of room temperature to1100℃. The yield strength and tensile strengths declined gradually, and the ductility of both alloys increased as the testing temperature was increased to 300℃. All the three properties reached a plateau at temperatures between 300 and 500℃ in the case of 95W-3.5Ni-l.5Fe and at temperatures between 350 and 700℃ in the case of 95W-4.5Ni-0.5Co. Thereafter, the ductility as well as yield and tensile strengths decreased considerably. 展开更多
关键词 liquid phase sintering tungsten alloys tensile testing mechanical properties
下载PDF
Factors Affected HIV Testing and HIV Infection among Internet-based Self-testing MSM Who Never Tested for HIV in Beijing,China 被引量:2
14
作者 JIN Xia XIAO Dong +5 位作者 XU Jun Jie SMITH M Kumi XIU Xiang Fei DING Zheng Wei CAO Ning Xiao BAO Yu Gang 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2020年第10期775-779,共5页
Around half of the men who have sex with men(MSM)have never been tested for human immunodeficiency virus(HIV),even though the health authorities promoted a massive scale-up of HIV testing and counseling in health faci... Around half of the men who have sex with men(MSM)have never been tested for human immunodeficiency virus(HIV),even though the health authorities promoted a massive scale-up of HIV testing and counseling in health facilities[1].HIV self-testing has been recommended by the World Health Organization as a user-friendly,convenient,rapid,and accurate approach to access HIV testing[2].An internet-based provision of self-testing services may be critical to the rollout of HIV self-testing,but more research is needed. 展开更多
关键词 testing massive CONVENIENT
下载PDF
Performance of identical rockbolts tested on four dynamic testing rigs employing the direct impact method 被引量:1
15
作者 Charlie C.Li John Hadjigeorgiou +5 位作者 Peter Mikula Greig Knox Bradley Darlington Renee Royer Andrzej Pytlik Michael Hosp 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2021年第4期745-754,共10页
Impact drop tests are routinely used to examine the dynamic performance of rockbolts.Numerous impact tests have been carried out in the past decades on independently designed,constructed and operated testing rigs.Each... Impact drop tests are routinely used to examine the dynamic performance of rockbolts.Numerous impact tests have been carried out in the past decades on independently designed,constructed and operated testing rigs.Each laboratory has developed testing procedures;thus,the results are often reported in different ways by various laboratories.The inconsistency in testing procedures and reporting formats presents a challenge when comparing results from different laboratories.A series of impact tests of identical rockbolts was carried out using the direct impact method(i.e.the mass free-fall method)on the rigs in four laboratories in different countries.The purpose of these tests was to investigate the level of consistency in the results from the four rigs.Each rig demonstrated a high level of repeatability,but differences existed between the various rigs.The differences would suggest that there is noticeable equipment-dependent bias when test results obtained from different laboratories are compared.It was also observed that the energy dissipated for the plastic displacement of the bolt was smaller than the impact energy in the tests.The average impact load(AIL)and the ultimate plastic displacement(D)of the bolt describe the ultimate dynamic performance of the bolt.In the case where the bolt does not rupture,the specific plastic energy(SPE)is an appropriate parameter in describing the impact performance of the bolt.Two other relevant parameters are the first peak load(FPL)and the initial stiffness(K)of the bolt sample.The information from this test series will guide the formulation of standardised testing procedures for dynamic impact tests of rockbolts. 展开更多
关键词 Dynamic test Drop test Impact test Rockbolt Rock reinforcement Ground support
下载PDF
Women's willingness to be tested for human immunodeficiency virus during pregnancy: A review 被引量:4
16
作者 Merav Ben-Natan Yelena Hazanov 《World Journal of Virology》 2015年第3期245-254,共10页
Mother-to-child-transmission of human immunodeficiency virus(HIV) is a primary cause of pediatric infections with HIV. Many of these infections involve women who were not tested early enough in pregnancy, or who didno... Mother-to-child-transmission of human immunodeficiency virus(HIV) is a primary cause of pediatric infections with HIV. Many of these infections involve women who were not tested early enough in pregnancy, or who didnot receive prevention services. HIV testing of pregnant women is considered to be one of the key strategies for preventing mother-to-child-transmission of HIV, but HIV testing rates among pregnant women in various countries remain suboptimal. Understanding the factors relating to women's willingness to be tested for HIV during pregnancy is critical for developing strategies to increase HIV testing rates among pregnant women. Extensive research points to various factors relating to women's willingness to be tested for HIV during pregnancy, and various recommendations aimed at improving testing rates among pregnant women have been suggested based on the research. In light of the goals set by the United Nations to reduce the rate of infants infected with HIV, it is necessary to summarize what is currently known regarding factors related to women's willingness to be tested for HIV during pregnancy. The purpose of this review is therefore to examine factors related to women's willingness to be tested for HIV during pregnancy, and to summarize recommendations for practice and further research. 展开更多
关键词 FEMALE Human IMMUNODEFICIENCY virus infection PREGNANCY Testing/screening Patient acceptance of health CARE Research
下载PDF
Loader and Tester Swarming Drones for Cellular PhoneNetwork Loading and Field Test: Non-stochasticParticle Swarm Optimization 被引量:1
17
作者 Amir Mirzaeinia Mostafa Hassanalian +1 位作者 Mohammad Shekaramiz Mehdi Mirzaeinia 《Journal of Autonomous Intelligence》 2019年第2期14-24,共11页
Cellular network operators have problems to test their network without affecting their user experience. Testingnetwork performance in a loaded situation is a challenge for the network operator because network performa... Cellular network operators have problems to test their network without affecting their user experience. Testingnetwork performance in a loaded situation is a challenge for the network operator because network performance differswhen it has more load on the radio access part. Therefore, in this paper, deploying swarming drones is proposed to loadthe cellular network and scan/test the network performance more realistically. Besides, manual swarming dronenavigation is not efficient enough to detect problematic regions. Hence, particle swarm optimization is proposed to bedeployed on swarming drone to find the regions where there are performance issues. Swarming drone communicationshelps to deploy the particle swarm optimization (PSO) method on them. Loading and testing swarm separation help tohave almost non-stochastic received signal level as an objective function. Moreover, there are some situations that morethan one network parameter should be used to find a problematic region in the cellular network. It is also proposed toapply multi-objective PSO to find more multi-parameter network optimization at the same time. 展开更多
关键词 Particle Swarm OPTIMIZATION SWARMING DRONE Cellular NETWORK Radio OPTIMIZATION Loaded NETWORK Test
下载PDF
An innovative tester system for measuring mechanical property of foundry molding sand
18
作者 Zuxi XIE Qingchun XIANG +1 位作者 Xu WANG Dongmei LIU 《China Foundry》 SCIE CAS 2004年第2期99-105,共7页
A new intelligent tester system for measuring multiple mechanical properties of foundry molding sand is introduced and has been patented for the invention in China. The testing process can be simultaneously controlled... A new intelligent tester system for measuring multiple mechanical properties of foundry molding sand is introduced and has been patented for the invention in China. The testing process can be simultaneously controlled with a build-in chip microcomputer communicating with a PC through a serial port. The testing system applies dynamic testing technology. During the measurement for compression, relaxation, shearing and tensile processes of sand specimens, the corresponding characteristic curves and eight mechanical property parameters can be obtained in a short time, simply by consecutively testing on four sand specimens. The properties and parameters to be measurable by the tester include compressive strength, elastic modulus, plastic deformation threshold, springback potential, shear strength, shear deformation limit, toughness and tensile strength. These properties and parameters for sand specimens can be defined as the corresponding characteristic curves with precise physical meanings, carried out by the tester, Two of them, namely plastic deformation threshold and springback potential, as well as their testing methods, have been invented for the first time. The testing system applying advanced data measurement technology as well as performing excellent functions is an important breakthrough and creativity in foundry molding sand property testing field. The parameters acquired by the testing system are stable, accurate and reliable. The test data can be instantly displayed or printed out or stored in the PC. As evidence, many experimental data obtained by the tester practically from both laboratory and foundry floor tests indicate that the tester system can be widely applied in foundry industry. 展开更多
关键词 molding sand mechanical property testing system
下载PDF
Intelligent Tester for Geotextiles Products-Determination of Water Flow Capacity in their Plane
19
作者 冯玉生 宋百平 《Journal of Donghua University(English Edition)》 EI CAS 2004年第6期152-155,共4页
Geotextiles and geotextile-related products Determination of water flowcapacity in their plane has just National standard. But has not a formal instrument at present. There are many kinds of geotextile and also lots o... Geotextiles and geotextile-related products Determination of water flowcapacity in their plane has just National standard. But has not a formal instrument at present. There are many kinds of geotextile and also lots of factors influential to the penetration coefficient thereof. The intelligent tester may be involved in testing penetration coefficient under different pressures/gradients resulted in fine repeatability controlled intelligently by microcomputer system. 展开更多
关键词 Geotextile PENETRATION coefficient intelligent test
下载PDF
Study on Temperature Distribution of Specimens Tested on the Gleeble 3800 at Hot Forming Conditions
20
作者 Tao Gao Long Ma Xiao-Guo Peng 《Journal of Electronic Science and Technology》 CAS 2014年第4期419-423,共5页
Taking Ti-6Al-4V specimens into consideration, the coupled thermal-electrical finite element model has been developed in Abaqus/Explicit to simulate the heating process in Gleeble 3800 and to study the temperature his... Taking Ti-6Al-4V specimens into consideration, the coupled thermal-electrical finite element model has been developed in Abaqus/Explicit to simulate the heating process in Gleeble 3800 and to study the temperature history and distribution in the specimen. In order to verify the finite element (FE) results, thermal tests are carried out on Gleeble 3800 for a Ti-6Al-4V specimen with a slot to in the centre of the specimen. The effects of the specimen size, heating rate, and air convection on the temperature distribution over the specimen have been investigated. The conclusions can be drawn as: the temperature gradient of the specimen decreases as the specimen size, heating rate, and vacuuming decrease. 展开更多
关键词 Coupled thermal-electrical simulation hot forming thermo-mechanical testing temperaturedistribution.
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部