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结直肠癌是一组具有一系列基因组和表观基因组改变的常见恶性肿瘤。其分子病理学的进展可以更好地从发病机制角度理解该肿瘤，从而更加精准地指导治疗。该文旨在概述结直肠癌的分子病理进展及其生物标志物对治疗的指导意义，并讨论了具有临床价值的结直肠癌的分子分型，以便读者更好地理解结直肠癌的分子病理进展及其临床意义。.

In the early 20th century, the Chinese Society of Medical History was the only specialty society accepting members with traditional Chinese medicine background in the Chinese medical association. Therefore, it is of special significance to study the TCM members of the early Chinese Society of Medical History. By combing the medical journals of this period and referring to the researches today, this paper makes a comprehensive investigation on the life stories and academic works of the early 14 TCM doctors and scholars of the Chinese Society of Medical History, so as to understand their contributions to the development of Chinese medicine and the institute of medical history in this special historical period.20世纪前期，中华医史学会是中华医学会这一西医学术团体中唯一接收中医背景成员的专科学会。因此，对中华医史学会早期中医会员的研究有着特殊的意义。通过梳理这一时期的医学杂志，并参考今人研究，本文对中华医史学会早期14位中医医生、学者的生平事迹和学术著作进行了较为全面的整理，从而了解他们在这一特殊历史时期为中国医学发展及医史研究所做出的贡献。.

《医方类聚》成书于世宗二十七年(1445)，是朝鲜医学之集大成者，书中引用了《妇人大全良方》的部分内容。以朝鲜原书覆刻的日本文久元年(1861)本影印本为《医方类聚》底本，元勤有书堂刻本缩微胶片(简称元刊本)为《妇人大全良方》底本，对《医方类聚》引用《妇人大全良方》内容进行比较研究，《妇人大全良方》在《医方类聚》直接引用42次，其中《妇人门》41次，《小儿门》1次；间接引用分为单行大字和双行小字2种，无明显规律。同时发现，直接引文是根据体例和内容进行了相关调整，引文与元刊本差异大多较小，可以互相修正、补充，对校勘《妇人大全良方》有重要参考价值。.

良性前列腺增生症（BPH）引起的下尿路症状（LUTS）是中老年男性最常见的疾病之一，严重影响男性的生活质量。BPH微创手术已经被公认为安全有效的治疗方法，同时也使得医源性尿道损伤的发生概率呈上升趋势，其中手术引起尿道狭窄并发症，可能会导致患者需要定期接受尿道扩张治疗，甚至终身携带膀胱造瘘管，严重影响术后生活质量。通过完善术前评估、规范手术操作、加强术后护理等措施能够减少尿道狭窄发生的概率，利于改善疾病症状及提高患者术后生活质量。.

单克隆免疫球蛋白可通过直接或间接机制引起多种形式的肾脏损伤，该组疾病临床和病理表现多种多样，及早识别相关临床线索并做出准确诊断对治疗和预后至关重要。综合分析患者的肾脏表现和免疫血清学特点有助于推断肾损害类型，最终确诊有赖于肾组织活检病理。本文就不同类型单克隆免疫球蛋白相关肾损害的临床和病理特点作一介绍，并对该类疾病的诊断思路进行简要总结。.

This article explores the development process of Japanese kampo medicine granules, which may be related to the popularization of convenience coffee in Japan in the 1940s. The development achievements were made mainly by two people: Itakura Takeshi and Watanabe Takeshi.Itakura Takeshi made the granule in 1944, and Watanabe Takeshi published an article about granule in 1947. In 1950, the granules were applied to clinic by Hosoya Shirou. In 1957, Kotaro pharmaceutical Co. Ltd was the first to sell granules in the market. Ten years later, in 1967, five classes and six kinds of drugs entered the Japanese medical insurance system, which has epoch-making significance in the history of the development of kampo medicine. Later, the guidelines of application and management for granules-日本汉方颗粒剂的开发可能与20世纪40年代日本便利咖啡的普及有关，其中板仓武和渡边武做出了重要贡献。1944年板仓武制成颗粒剂，1947年渡边武公开发表有关颗粒剂的文章。1950年细野史郎将颗粒剂应用于临床。1957年小太郎汉方制药公司首先销售颗粒剂，到1967年已有5类6种药物进入日本医疗保险体系，这在汉方发展史上具有划时代的意义。之后，颗粒剂的使用指导和管理原则主要由日本厚生省主持召集专家制定，《一般用汉方处方手册》在临床应用中影响很大。同时，日本汉方生药制造协会在药物生产和销售过程中发挥了很好的协调作用。.

To research the composite effect of partially concrete-encased composite columns, the axial compression analysis of three groups of 12 specimens (six H-shape steel partially concrete-encased composite columns and six H-shape steel columns) was conducted by using the commercial finite element software ANSYS. The results show that partially concrete-encased composite columns possess sound mechanical performance as demonstrated by higher ultimate strength, deformability, stability and lateral stiffness than bare steel columns. The total cross-section of concrete and steel of partially concrete-encased composite columns both yield when specimens are damaged, showing better compatibility for deformation. Partially concrete-encased composite provides good restraint for H-shaped steel to prevent local buckling, and the H-shaped steel confines the concrete, increasing its strength and ductility. Moreover, there is superior interaction effect between the concrete and the steel.

The stationed system for detached medical officer, designated by the Royal Hanlin Department, was an important management system in the Song Dynasty for medical aid and epidemic prevention. The selection of the officers was based on the test results of the candidates. The dispatch of such medical officers was considered comprehensively on the local conditions, with priority given to those provinces and counties in shortage of such officers, and sent them in order based on the duration of their working time.The primary responsibility of the stationed medical officers was to provide medical services to locally stationed troops, at the same time also involved in treating and saving people as epidemics occurred in local places. The term of their service was two years. The system is a kind of relatively mature medical management practices, which could improve the level of local army medical services and control the occurrence and spread of epidemics effectively.驻泊医官制度是宋代政府进行医疗救助、疫情防控的一项重要管理措施，翰林医官院是驻泊医官的选派机构；选派时按照考试成绩高低管理，缺乏医官的州郡优先安排，并按医官供职先后顺序等综合考虑予以分遣；驻泊医官的主要职责是为所驻扎的地方军队提供医疗服务，同时在地方发生疫情时亦参与救治民众；驻泊医官任期为2年。该制度是一种较为成熟的医者管理制度，能够提高地方军队的医疗服务水平，有效防控地方疫情的发生、蔓延。.

To investigate the expression of immunoglobulin A (IgA) in human mesangial cells (HMCs).The HMCs were cultured. The subcellular location of IgA was detected by immunofluorescence staining; the transcripts of Igα,Igκ and IgΛ constant region were detected by reverse transcription-polymerase chain reaction (RT-PCR) and further analyzed by DNA sequencing. The expressions of Igα and IgΛ were detected at transcription level by Western blot after the cytoplasmic protein extraction. The culture supernatant was collected to explore whether IgA could be secreted out of the cell and the protein was further analyzed by mass spectrometry after being purified by affinity chromato-graphy with jacalin-sepharose. The results of DNA sequencing and mass spectrometry were aligned with the mRNA and amino acid sequences in the National Center of Biotechnology Information (NCBI) database.By immunofluorescence staining, we detected the presence of IgA heavy chain Igα, light chain, both Igκ and IgΛ in expressions of transcripts of Igα1, Igα2, Igκ and IgΛ in the HMCs and the alignment of the sequences of the RT-PCR products with those of the IgCα1, IgCα2, Igκ and IgΛ mRNA in the NCBI database exhibited that the similarities were 99%, 97%, 98% and 97%, respectively. Western blot showed Igα and IgΛ expressions in the cell lysate and secretion of Igα1 and Igα2 heavy chains in cell culture supernatant. To further explore the protein that secreted into the supernatant, after supernatant affinity chromatography with jacalin-sepharose, the proteins were separated by sodium dodecyl sulfonate-polyacrylamide gel electrophoresis (SDS-PAGE) and the band approximating to 65 000 was cut and sent to mass spectrometry. The results were aligned with the amino acid sequences of Igα1 and Igα2 constant region in NCBI database, showing that amino acids between No.52 and No.104, amino acids between No.154 and No.221, amino acids between No.276 and No.327 from IgCα1 and amino acids between No.52 and No.113, amino acids between No.151 and No.204, amino acids between No.251 and No.314 from IgCα2 were the same with those derived from B cells.Our fin-dings suggested that HMCs could synthesize and secret IgA.

Specific High Electron Mobility Transistors (HEMTs) have been realized and characterized. At 4.2 K, with a drain-source current Ids of 1.55 mA and drain-source voltage Vds of 100 mV, the transistor has the following electrical characteristics: a transconductance and an output conductance of 69 and 3.8 mS, respectively, leading to an intrinsic voltage gain of 18; an input gate-source capacitance Cgs of about 31 pF; and a gate leakage current less than 0.2 pA. An equivalent input noise voltage lower than 1 nV/Hz1/2 at 1 kHz has been achieved when Ids=1.55 mA at Vds=100 mV. Hence, our results show that the specific HEMTs should be a suitable transistor for future ultra-low noise deep cryogenic low-frequency high-impedance readout electronics.

Specific HEMTs (High Electron Mobility Transistors) with different gate geometries have been realized on the same AlGaAs/GaAs heterojunction. Under the same operating conditions with a power consumption of 30 μW, experimental results at 4.2 K and low frequency range show that the input voltage noise is almost inversely proportional to the square root of the input capacitance: a noise value as low as \(0.46~\mathrm{nV}/\sqrt{\mathrm{Hz}}\) at 1 kHz has been obtained with an input capacitance of about 100 pF.

The method of high temperature and pressure ammonia solution treatment to improve the interfacial performances of carbon fiber/epoxy composites is discussed in this study. Besides, the influence of high temperature and pressure ammonia solution treatment on carbon fiber and its reinforced epoxy composite interface performance were studied. The untreated and treated carbon fibers were characterized by monofilament tensile test, X-ray photoelectron spectroscopy (XPS), and atomic force microscope (AFM). The interfacial adhesion of the untreated and treated carbon fibers reinforced epoxy resin composites were also evaluated by interface shear strength (IFSS) test, interlaminar shear strength (ILSS) test, and fracture morphology analysis. It was found that the interfacial adhesion of composites increased greatly after high temperature and pressure ammonia solution treatment. The improvement of interfacial adhesion was attributed to the increase of polar functional groups and surface roughness of carbon fibers surface after treatment. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

With economic globalization, the rate and effects of culture shock stress in expatriates and their families are expected to increase. The stressor may occur from the micro-environment, the macro-environment, or the mega-environment. The effects of stress are frequently due to predictable reactions such as insecurity, distress, and homesickness. These symptoms can progress to more severe psychosomatic symptoms, including depressive reactions and overt psychopathic behavior. Cross-cultural training programs are currently the best preventive strategy for culture shock and subsequent stress; however, the true efficacy of these programs is not well characterized. Substance abuse is probably a significant underlying problem for international business travelers; however, the true magnitude and effects of this issue are not well characterized in the expatriate community. There are substantial opportunities for additional medical research in these areas.

Individual ZnO nanowire transistors are fabricated, and their sensing properties are investigated. The transistors show a carrier density of 2300μm−1 and mobility up to 6.4cm2∕Vs, which are obtained from the ISD−VG curves. The threshold voltage shifts in the positive direction and the source-drain current decreases as ambient oxygen concentration increases. However, the opposite occurs when the transistors are under illumination. Surface adsorbates on the ZnO nanowires affect both the mobility and the carrier density. Our data are helpful in understanding the sensing mechanism of the gas sensors.

We report on field emission from SnO2 nanobelt arrays with the length of about 90 μm grown on silicon substrates. The turn-on field of the nanobelt arrays at the current density of 1μA∕cm2, is 4.5, 3.0, 2.4, and 2.3V∕μm as the distance between anode and cathode (d) is 0.1, 0.2, 0.35, and 0.5 mm, respectively. The current density rapidly reaches 2.1mA∕cm2 at the electrical field of 4.4V∕μm at d=0.35mm. The current density is higher than or comparable to those of the carbon nanotubes and other one-dimensional nanostructured materials. We also discuss the mechanism of high current densities and estimate the enhancement factor according to both the Fowler–Nordheim law and the reported model on micrometer-long of carbon nanotubes.

Gas sensors have been fabricated from multiwalled carbon nanotubes (MWNTs) coated with a thin tin oxide layer, and have been used to detect oxidizing and reducing gases down to a ppm level. The barriers between the tin oxide nanocrystal grains on the MWNTs dominate the sensor resistance in different gases, and the conducting carriers in the MWNTs have a low resistance, which make the resistance of the sensors much lower than that of SnO2 nanobelt sensors. The resistance is 130kΩ in air, 230kΩ in 2ppm NO2, and 2.8MΩ in 50ppm NO2, so that impedance matching with amplifying circuits can be easily achieved.

Electronic transport through individual ZnO nanowires has been investigated. The current increases linearly with the bias and the conductance jumps upon ultraviolet illumination. The increase rate upon the illumination is much faster than the decrease rate as the light is off. The decrease rate under vacuum is slower than that in air. These phenomena are related to the surface oxygen species and further confirmed by in situ current–voltage measurements as a function of oxygen pressure at room temperature. Also, the conductance increases greatly as the temperature is raised. These results demonstrate that the surface oxygen species dominate the transport process through individual ZnO nanowires, which indicates their potential application to room temperature gas sensors.

Transport properties of a single multiwalled carbon nanotube (MWNT) have been investigated in vacuum at room temperature. The MWNTs show the large current carrying capacity at large bias due to the ballistic transport. The conductance for a single MWNT around zero bias is 0.4G0, and increases almost linearly with the applied voltage until it reaches its acmes. Being the signature of the ballistic transport for MWNTs, the conductance acmes are observed at the bias of ±5.8 V equal to ±2γ0/e, where γ0 is the π bonding energy for carbon nanotubes. Our calculation shows a similar curve to our experimental results, which further indicates the ballistic transport through the single MWNT.

1,2-dichloroethane(1,2-DCE) is toxic, especially by inhalation due to its high vapour pressure. Inhalation of concentrated 1,2-DCE vapor can induce effects on the human nervous system, even encephalopathy. However, 1,2-DCE toxic encephalopathy has seldom been reported, and no adequate data were available to evaluate the encephalopathy of 1,2-DCE in experimental animals. The aim of the present study was to establish a toxic experimental animal model induced by 1,2-DCE. Dose effect and time effect of 1,2-DCE on the nervous system were detected. The rats were treated by 1,2-DCE at various concentrations of 0, 2.5, 5.0, 10.0 g/m3 for 6 h and treatment of rats at 10.0 g/m3 for 0, 3, 6, and 12 h. Morphology of brain tissue was observed by HE staining and TEM under light and electron microscope, besides water contents in the cortex and medulla of rats were analyzed. The results indicated that 1,2-DCE induced abnormal histopathology, and significantly higher water content were confirmed in the cerebral cortex of toxic animal model in a dose- and time-dependent manner. To declare that 1,2-DCE could induce toxic encephalopathy with a pathological feature of cerebral edema is very important for the medical rescue in urgent toxic accidents.

We report on DC and noise characteristics at 4.2 K of High Electron Mobility Transistors (HEMTs) which have been realized at LPN/CNRS. This work is aimed to develop high performance, low-power, low-frequency noise and low-temperature field-effect transistors for the future cryoelectronics. A high quality two-dimensional electron gas (2DEG) based on AlGaAs/GaAs heterostructure has been used to realize appropriately designed HEMTs with different gate configurations. With these transistors, we have obtained, for example, a transconductance of about 100 mS and a voltage gain of 26 with a power dissipation of less than 100 mu W at 4.2 K; and a corresponded equivalent input voltage noise of 1.2 nV/Hz(1/2) at 1 kHz and as low as 0.12 nV/Hz(1/2)s at 100 kHz.

Occupational safety and health programmes are economically beneficial China, with a population of 1.2 billion, is the most populous country. Approximately 700 million are in the active labour force, of which a large proportion is engaged in construction, mining, and other occupations with potential exposure to silica. The number of workers exposed to silica containing dusts may be as high as 12 million. Pneumoconiosis has long been the most serious and yet preventable occupational disease in China. New cases are estimated at 7500 to 10 000 annually, representing more than 70% of the total reported cases of occupational diseases in recent years.1–3 The cumulative number of confirmed pneumoconiosis cases recorded in China between 1949 and 2001 reached 569 129. The majority of the cases occurred in the mining industries, particularly in coalmines, resulting in anthracosilicosis, which accounted for about 40% of the disease.1 Among them, more than 25% had died. In addition to confirmed cases, a 1986 nationwide survey found that an even greater number of exposed workers (around 600 000) were classified as suspected cases.1–3 Pneumoconiosis is a progressive and irreversible fibrogenic lung disease that results in not only human suffering but also unaffordable economic burdens. In this paper, we estimate the economic burden of pneumoconiosis in China. The methodologies of estimating economic burdens of occupational diseases vary from disease to disease and from investigation to investigation, dictated primarily by the data available.4–8 We use the traditional human capital approach, which divides costs into direct and indirect categories. In our analysis, direct costs include medical expenses, work absence losses, and management costs, whereas indirect costs include production and profit/tax losses due to work absences. The data in our analysis are derived from two previous investigations in China.9,10 The first investigation …

Si JFETs have been for decades the lowest noise field-effect transistor (FET) for high-impedance and low-frequency readout electronics. However, they are based on nondegenerate carriers, and their operating temperature is limited to higher than 100 K due to freeze-out of carriers. Being based on degenerate carriers, the HEMT has no low-temperature limit. Here, we report on the experimental results of specially designed HEMTs made at CNRS/LPN. These HEMTs, with different input capacitances from 92 pF to 5.3 pF, have been characterized from 4.2 K to 77 K, and show a power consumption of 100 μW or below. At 4.2 K, the lowest input noise voltage, 6 nV/Hz 1/2 at 1 Hz, has been obtained with the HEMT having the largest input capacitance; the lowest input noise current of about 3 aA/Hz 1/2 at 1 Hz has been observed with the HEMT with the smallest input capacitance; and the white noise voltage in these HEMTs is of about 0.2 nV/Hz 1/2 . By increasing the temperature from 4.2 K to 77 K, noise voltage and noise current increase, but their values are limited within a factor of about 3 compared to their lowest values at 4.2 K. Our results show that the HEMT can be a promising transistor to fill the gap for FETs below 100 K for high-impedance and low-frequency readout electronics.

Based on expert recommendations, the World Health Organization (WHO) recommended the Neurobehavioral Core Test Battery (NCTB) in 1983 to detect neurotoxicity in world-wide populations. The NCTB consists of 7 neurobehavioral tests (Digit Symbol, Digit Span, Benton visual memory test/recognition form, Santa Ana dexterity test, Simple Reaction Time, Pursuit Aiming II, and Profile of Mood States). Research with the NCTB provides the context for the results of a mini-symposium held in 1999 to discuss the lessons learned about using the NCTB in working populations. Speakers from Africa, Asia, Europe, and North America reviewed data from 94 studies using the NCTB, including 63 from China, 13 from Korea, 11 from Poland, three from South Africa, three from the USA, and one from Ecuador. Although a consensus was not sought in the symposium, the key lessons learned that emerged from the various presentations, were: * The NCTB is effective in testing adults with 12 or more years of formal education, but can not reliably test persons with less than 9 years of education. * People from cultures very different from those in Europe and North America (eg, aboriginal and African cultures) may not be tested effectively by the NCTB, although others such as at least some Asian populations, can be. To address this problem, the construct validity of the NCTB should be established in a wide range of countries. * The POMS measures of emotion proved to be very sensitive to neurotoxic exposures in several countries, but the POMS was the NCTB test most affected by cultural differences. The Digit Symbol or the Milan modification of that test was also highly sensitive to neurotoxic exposures. * Examiner drift following training to administer the NCTB is a significant problem in technically trained Examiners. Pursuit Aiming II is very difficult to score reliably.

The main goals of the study were to elucidate the mechanism of Al-induced behavioral toxicity and to explore the possible link between the changes in the metabolism of monoaminergic or cholinergic transmitters and neurobehavioral effects. Three groups (12 rats in each group) were fed with aluminum chloride in drinking water (1600 mg/l) ad libitum through a 90-day exposure period. The controls were fed with distilled water. From the 60th to 90th day of treatment, two of the three Al-treated groups were administered with L-dopa (220 mg/kg.bw) and eserine (0.4 mg/kg.bw) by gavage, respectively. A two-item neurobehavioral test battery consisting of step down test and Morris water maze task was used for rats after three months treatment. In the step-down test, markedly shortened the step-down latency (SDL) and the number of step-down (NSD) were observed in the Al-treated group (P0.05, vs. control). On the contrary, only slight changes were found in the rats treated with aluminum combined with L-dopa or eserine (P0.05, vs control). In eserine and L-dopa antagonized groups, the mean escape latencies of Morris water maze approached a level close to that of the controls (P0.05). The results showed that the Al-induced memory and learning impairment could be reduced by L-dopa or eserine. It is suggested that the depletion of dopaminergic and cholinergic transmitters in the central nervous system might play an important role in Al-induced neurotoxicity.

We report on the results obtained from specially designed high electron mobility transistors at 4.2 K: the gate leakage current can be limited lower than 1 aA, and the equivalent input noise-voltage and noise-current at 1 Hz can reach 6.3 nV/Hz1∕2 and 20 aA/Hz1∕2, respectively. These results open the way to realize high performance low-frequency readout electronics under very low-temperature conditions.

The cytotoxic effects of lead acetate on primary cultured astrocytes and Schwann cells (SCs) were studied for comparing the sensitivity of the two kinds of cells and exploring the possible mechanism of lead cytotoxicity. The results indicated that the number of astrocytes detached from the culture surfaces were dependent on the concentration and time of lead exposure. Under phase contrast microscopy, increases in the number of vacuoles were observed at doses of 50 and 100 micrograms ml-1 lead after 96 h of lead exposure for astrocytes and 1, 5 and 10 micrograms ml-1 lead after 24 h of lead exposure for SCs. By scanning electron microscopy, the surface changes in astrocytes began to appear at the dose of 10 micrograms ml-1 lead, whereas in SCs it began in 1 microgram ml-1 lead. By transmission electron microscopy, astrocytes exposed to 10, 50 and 100 micrograms ml-1 lead had increased lysosomal densities, the presence of nuclear inclusions and enlargement of rough endoplasmic reticulum, whereas SCs exposed to 1 microgram ml-1 lead began to show swelling of mitochondria and endoplasmic reticulum, cytoplasmic vacuolizations and numerous myelinoid bodies. Increases in the content of lactic dehydrogenase (LDH) leakage from the astrocytes exposed to 100 micrograms ml-1 lead and SCs exposed to 1, 5 and 10 micrograms ml-1 lead were observed, respectively. Decreases in sulphydryl group (SH) levels in astrocytes exposed to 50 and 100 micrograms ml-1 lead and SCs exposed to 1, 5 and 10 micrograms ml-1 lead were also observed. A dose of 1.0 mmol l-1 reduced glutathione (GSH) and 2.0 mmol l-1 dithiothreitol (DTT) could protect astrocytes from lead-induced SH decrease and LDH leakage. Doses of 10-100 mumol l-1 cAMP were shown to have a protective effect on lead-induced SH decrease in SCs. No significant changes of GSH or lipid peroxidation (LPO) were observed in astrocytes. The results indicated that SH was involved in lead-induced cytotoxicity of astrocytes and SCs, and SCs were more sensitive to lead-induced cytotoxicity than astrocytes.

Neurobehavioral and neurochemical effects of occupational lead exposure were investigated by WHO Neurobehavioral Core Test Battery (NCTB) testing and a series of monoamine neurotransmitters and their metabolites analyzing in workers from lead smeltery and storage-battery manufacturing factory and matched controls. Indicators of lead exposure, the blood lead (PbB) and zinc protophorphyrin (ZPP) levels were found significantly higher in the exposed group compared with that of the controls (70.55 micrograms/dL vs 3.67 micrograms/dL; and 294.92 micrograms/dL vs 38.32 micrograms/dL, respectively). Furthermore, elevated urinary homovanillic acid (HVA) and impairment of certain neurobehavioral performances were also found in the lead exposed workers; the latter included attention/response speed, manual dexterity, perceptual-motor speed, visual perception/memory, and motor speed/steadiness. Positive or negative correlations were observed between certain parameters. Thus, homovanillic acid (HVA) is positively correlated with PbB and ZPP; dopamine (DA) negatively correlated with Benton visual retention (BVR); and HVA negatively correlated with digit symbol (DSy), BVR, and pursuit aiming (PA). It is suggested that the alterations of dopamine and its metabolites HVA in urine associated with impairment of neurobehavioral function might be served as biomarkers of lead-induced neurotoxicity.

For decades, high-impedance and low-frequency readout electronics with the lowest noise level is based on silicon JFETs (Junction Field-Effect Transistors) with an equivalent input noise voltage level of about 1 nV/Hz1/2 at 1 kHz. But their operating temperature is limited to be higher than 100 K due to their intrinsic structure. It is well known that HEMTs (High Electron Mobility Transistors) are intrinsically available for very low temperature operation, but conventional HEMTs suffer high gate leakage current and large channel low-frequency noise under cryogenic condition. In order to overcome these two major issues, we have extensively investigated the conventional HEMTs at 4.2 K by the bias-cooling method. At a given working point, the dependence of the channel low-frequency noise on the gate leakage current has been found out and this has allowed us to devise a new transistor structure. Specific AlGaAs/GaAs HEMTs have then been fabricated. At 4.2 K, our HEMTs can attain a noise level lower than 0.8 nV/Hz1/2 at 1k Hz with an intrinsic gain Aint of 26 and an input gate-source capacitance of 46 pF, and their gate leakage current can be limited about 1 pA This result shows that our specific HEMTs may be a suitable transistor for future ultra-low noise deep cryogenic high-impedance and low-frequency readout electronics.

Meta-analysis was used to deal with the data collected in neurobehavioral toxicological studies to synthesize their findings quantitatively. Results revealed neurotoxic chemicals could cause changes in cognitive abilities, psychomotor function and emotion of persons exposed. However, each toxicant had its distinct effects on neurobehavior, for example, lead mainly impairs touch sense, memory, emotion and cognitive abilities, mercury does intelligence, concentration and motor stability, and carbon disulfide does eye-hand coordination. It suggested meta-analysis could be directive to selecting the best combination of neurobehavioral tests.

Dam rats were given Pb (0.58, 1.76, and 5.27 mmol.L-1), containing water ad lib from d 16 of gestation to weaning of the offspring on d 21 postpartum. The pups continued drinking the same water till the postnatal d 30. The neurobehavioral function of pups was tested. The second step-down latencies (SDL2) were shortened and the number of step-downs in 5 min (NSD) were increased in step-down test. The prolongation of the lapse of time in passing through the whole course (LTPWC) and the increase in number of entries into the blind alley (NEBA) were measured in water maze test. The number of ambulations and rearings were increased in locomotor activity. The results indicated that Pb exerts adverse effects on the learning ability and memory function, and induces hyperactivity in young rats.

Neuropsychological effects of lead exposure were studied with WHO recommended Neurobehavioral Core Test Battery (NCTB) and factor analysis in 78 workers occupationally exposed to lead and 76 nonexposed controls with mean blood lead levels of 2.14 mumol/L and 0.20 mumol/L, respectively. Except for the length of employment and average monthly income, there was no significant difference in other aspects of both groups. Lead-exposed workers with blood lead level or more than 2.72 mumol/L showed mild impairment to their motor coordination and memory functions. It also showed a dose-response tendency between blood lead levels and scores of five relevant factors.

To address the need for standardized test batteries, an expert group convened by the World Health Organization (WHO) and the U.S. National Institute for Occupational Safety and Health during 1983 proposed the Neurobehavioral Core Test Battery (NCTB) to identify nervous system effects of chemical exposures in human populations worldwide. To determine the feasibility of using the NCTB in varied cultures, a cross-cultural assessment was conducted under WHO auspices. Data were collected in 10 countries of Europe, North and Central America, and Asia from over 2300 males and females who were not exposed to chemicals at work, within five age ranges between 16 and 65. Results suggest that performance on two NCTB tests (Simple Reaction Time, Benton Visual Retention) is very similar in a broad range of countries and that performance on four other NCTB tests (Santa Ana, Digit Symbol, Digit Span, Aiming) is relatively more variable from country to country, in both males and females. However, data collected from very poorly educated males in one country revealed very low performance levels suggesting that the NCTB may not provide an adequate reference group for identifying (behavioral) neurotoxic effects in such populations. More research is thus needed on evaluating neurotoxicity in poorly educated subjects.

Chloroform has obvious hepato-, nephro-toxicity and carcinogenicity. In order to get necessary data for recommendation of maximum allowable concentration of chloroform in workplace, a series of studies were carried out. The results showed that exposed workers mainly distributed in the industries of perspex processing, production of refrigerants, drugs and pesticides. The exposure level ranged 4.27-147.91 mg/m3 in 119 air samples collected from 3 representative worksites, with 45.4% air samples below 20 mg/m3. The workers exposed to chloroform at 29.51 mg/m3 had slight liver damage indicated by the higher rates of abnormal serum prealbumin and transferrin levels than those of control workers. The neurobehavioral functions of these workers were also obviously affected, manifested as increases in scores of passive mood states and dose-related negative changes in neurobehavioral testing. The observed effect threshold concentration of subacute inhalation in rats was 592 mg/m3 according to the observation on the biochemical changes in liver tissue and abnormal activities of serum enzymes. Mainly based on the above results, we recommended 20 mg/m3 as the Maximum Allowable Concentration in workplace in China at present.

In order to investigate the distribution and excretion of sterigmatocystin, a carcinogenic mycotoxin, radioactively labelled compound was studied in rats. The highest concentration of radioactivity in serum appeared 3 h after administration of 0.5 microCi/g bw. The half-lives of distribution and excretion were 0.51 h and 43.9 h, respectively. The radioactivity was concentrated mainly in liver, stomach, kidney, duodenum and lung and to a lesser extent in fat, muscle, testis, rectum and bone. By 48 h, 56.4% had been excreted in faeces and 20.1% in urine. Biliary excretion may be the major route of excretion of sterigmatocystin.

Two kinds of In2O3 nanowires (NWs), i.e., straight and tapered ones, are grown from 20-nm-thick Au∕300-nm-thick In and 20-nm-thick Au∕1-μm-thick In films on glass at 400°C by a one-step annealing method, respectively. All the NWs are single crystalline. The growth of the NWs is initiated by Au catalyst particles via vapor-liquid-solid growth mechanism, and an additional side growth might be responsible for the nonuniform diameters of the tapered NWs. It is revealed that a certain content of oxygen in the In film facilitates the large-scale growth of the In2O3 NWs. The field-emission studies show that the In2O3 NWs on glass have a low turn-on electric field of about 4.3V∕μm. Our growth method has potential applications in the in situ fabrication and integration of the In2O3 NWs-based devices, especially with glass as substrates.

Nonlinear characteristics of the Fowler–Nordheim (F–N) plot for field emission from In2O3 nanowires (NWs) is investigated. The field emission from the aligned and nonaligned In2O3 NWs are measured and a stable emission with fluctuations less than 10% was obtained for the aligned In2O3 NWs. It is found that the nonaligned In2O3 NWs with a longer length have higher turn-on and threshold electric fields. Their F–N plots, showing pronounced nonlinear characteristics, are divided into several regions based on physical origins. Field penetration competes with surface states in influencing the field emission of the In2O3 NWs with increasing the electric field, which is responsible for the nonlinear characteristics of the F–N plots.

Constraints in the management of occupational hazards include problems with technical feasibility and costs of control measures. A pilot investigation of the effectiveness of a carbon disulfide (CS2) recovery system in the manufacturing of viscose rayon by means of cost-benefit analysis was conducted at a Shanghai viscose rayon factory. The annual amount of carbon disulfide recovered with the new system reached approximately 1 500 t in 1982. It is estimated that the company has made a net profit of 1 million yuan (about USD 500 000 at the time of the study) per year from this system (almost equal to 10% of the production value of the factory). This study documented a control measure that was both effective in reducing a hazard for workers and economically beneficial to the company.

Fifty-three workers in a battery factory, 52 solderers in a television factory, and 50 embroidery workers (a reference group) were studied. The average air lead levels of the three workplaces were 0.578 mg/m3, 0.002 mg/m3, and 0.001 mg/m3, respectively. Adverse effects in terms of clinical manifestations and biochemical criteria were evident among the battery factory workers. A significant dose-response relationship existed between the toxic effects and the air lead levels. The solderers showed no apparent abnormalities in comparison with the embroidery workers. The early clinical manifestations were dysfunction of the central nervous system, indigestion, arthralgia, and myalgia in the extremities. A positive association was observed between the prevalence of fatigue, mild abdominal pain, and arthralgia and the blood lead (PbB), urinary lead (PbU), and zinc protoporphyrin (ZPP) levels. The symptomatic threshold values of PbB, PbU, and ZPP were 30 micrograms/dl (1.5 mumol/l), 0.045 mg/l (0.2 mumol/l), and 40 micrograms/dl (0.7 mumol/l), respectively. The PbB, PbU, free erythrocyte protoporphyrin, and ZPP levels and the blood aminolevulinic dehydratase ratio could be used as indicators of lead exposure, although ZPP is preferred for a preventive monitoring program. The motor and sensory conduction velocities of the median nerve were slower in the exposed groups than in the reference group. No effects on behavioral function were observed among the solderers.

A neurophysiological study was carried out to examine peripheral neurotoxicity of extremely low levels of CS2, that is, less than 2 ppm (TWA-8hr) among Chinese viscose rayon workers. From the subjects who participated in a 1981 cross-sectional medical survey, 70 male workers exposed to CS2 and age-matched unexposed workers were randomly selected for the present neurophysiological examination. The conduction velocities of motor, sensory and slower motor fibres of the right ulnar nerve were measured using the same methods as those in the study by Seppäläinen (1974). Skin temperature was measured at the middle of the volar surface of the right forearm with a Thermistor thermometer. According to an earlier occupational hygiene survey in the plant, current personal exposures determined by a passive dosimeter method were very low; the average of daily exposure of 7 jobs studied was 1.45 ppm (range 0.2-5.0). Past and current area sampling data also suggested that occupational hygiene conditions regarding CS2 exposure in the plant had been extremely good for the previous 6 years. The present neurophysiological study clearly showed that significant reduction in the conduction velocities of motor and slower motor fibres of the ulnar nerve was detected as a consequence of chronic exposure to low levels of CS2. In the previous cross-sectional medical survey, no retinopathy was found among Chinese workers exposed to CS2 at this level. These results suggested that an effect of CS2 on the peripheral nerve would appear earlier than that on the retina.