mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
Transgenic woody plants for biofuel

Transgenic trees as a new source for biofuel have brought a great interest in tree biotechnology. Genetically modifying forest trees for ethanol production have advantages in technical challenges, costs, environmental concerns, and financial problems over some of crops. Genetic engineering of forest trees can be used to reduce the level of lignin, to produce the fast-growing trees, to develop trees with higher cellulose, and to allow the trees to be grown more widely. Trees can establish themselves in the field with less care of farmers, compared to most of crops. Transgenic crops as a new source for biofuel have been recently reviewed in several reviews. Here, we overview transgenic woody plants as a new source for biofuel including genetically modified woody plants and environment; main focus of woody plants genetic modifications; solar to chemical energy transfer; cellulose biosynthesis; lignin biosynthesis; and cellulosic ethanol as biofuel.
Diversity, regeneration status and population structure of gum-and resin-bearing woody species in south Omo zone, southern Ethiopia

South Omo Administrative Zone in Ethiopia is home to 18 indigenous ethnic groups whose livelihood is vulnerable due to recurrent drought and degradation. Despite the preliminary observation showing the rich dry-forest resource base that, if sustainably managed could enhance livelihoods and biodiversity conservation, there is lack of empirical data on its current status. We conducted a study aiming at quantifying the population status of gum-and resin-bearing species in two randomly selected districts, Hamer and Bena-Tsemay. Seventy-five quadrats (35 at Hamer and 40 at Bena-Tsemay) each measuring 400 m2 were established along line transects to assess species diversity and equitability, density, frequency, dominance, importance value and population structure. We recorded a total of 27 woody species of 12 families and 14 genera. Fifteen species (9 at Hamer and 14 at Bena-Tsemay) of the genera Acacia, Boswellia, Commiphora and Sterculia, were identified as either major sources of commercial gums and resins or their adulterants. Gum-and resin-bearing species comprised 56% and 57% of species richness, 48% and 50% of total density per ha, 95% and 98% of basal area, and 64% and 56% of importance values at Hamer and Bena-Tsemay, respectively. Diversity of the entire woody species assemblage and of the gum-and resin-bearing species was slightly higher at Bena-Tsemay (H= 2.61, 1.4) than at Hamer (H′= 2.48, 1.28), respectively. The diversity and abundance of the resource base suggest potential for development of value-added commercialization of gum and resins to enhance livelihoods and encourage sustainable management of the forest at these study areas. We recorded, however, declining natural regeneration of most gum-and resin-bearing species, and this calls for integrated and participatory species management and landscape rehabilitation.
胶质瘤细胞组蛋白去甲基化酶JMJD3表达降低

目的检测和分析组蛋白去甲基化酶含十字形结构域蛋白3(JMJD3)在胶质瘤及瘤旁脑组织中的表达。方法用组织芯片筛选出JMJD3表达阳性的胶质瘤组织,选取50例相关胶质瘤患者的石蜡标本,采用免疫组化SP法检测JMJD3在相关胶质瘤组织中的表达与定位以及与瘤旁组织中表达的差异,分析JMJD3与胶质瘤的相关性。结果通过组织芯片筛选,发现JMJD3在正常少突胶质细胞中有表达。在50例胶质瘤患者的石蜡标本中,15例标本肿瘤组织为阳性,35例瘤旁组织为阳性。结论与瘤旁脑组织相比,胶质瘤JMJD3的表达降低。
血清反应因子促进人腹膜间皮细胞的转分化

目的探讨血清反应因子(SRF)在人腹膜间皮细胞(HPMC)转分化中的作用。方法腹膜间皮细胞由腹膜透析(PD)患者透出液离心后进行培养,观察不同透龄患者的原代腹膜间皮细胞改变,并用免疫荧光细胞化学方法检测SRF及α平滑肌肌动蛋白(α-SMA)、Snail、E-钙黏素(E-cadherin)的表达。细胞经高糖刺激发生转分化后,将SRF siRNA转染至细胞中使SRF 下调,用免疫荧光细胞化学技术及Western blot法检测E-cadherin和α-SMA、Snail的表达。采用染色体免疫共沉淀(ChIP)及报告基因方法检测SRF与Snail的结合情况。结果无菌收集50例PD患者透出液,原代培养HPMC,随着透析时间的延长,细胞从铺路石样逐渐转变为成纤维细胞样;SRF表达显著增强时,间质标志分子α-SMA的表达增强,而上皮标志分子E-cadherin 表达减弱。永生化的HPMC经高糖刺激72 h使其发生转分化后,用小干扰RNA使SRF沉默。与对照组相比,免疫荧光细胞化学染色显示SRF下调后,α-SMA、Snail的表达明显减弱,而E-cadherin表达明显增强;Western blot结果显示SRF的表达水平降低时,E-cadherin表达升高,而α-SMA、Snail的表达明显减少。ChIP结果提示,SRF可与Snail启动子区2个结合位点SRE1和SRE2结合,报告基因结果显示,SRF主要与SRE2位点结合并启动Snail的表达。结论SRF在已发生间充质转分化的HPMC 或腹膜纤维化时高表达,可能通过启动Snail表达来促进HPMC转分化。
论养阴法治疗慢性乙型病毒性肝炎

慢性乙型病毒性肝炎(以下简称“乙肝”)由慢性乙肝病毒感染人体所致,属中医温病范畴,其起始病因是湿热疫毒之邪侵犯机体,留滞经络,伏于肝脾,引起肝郁气滞,肝郁日久化热,气滞血瘀亦可化热,疾病后期引起肝肾阴虚或肝肾阳虚。有热必伤阴津,正如吴鞠通所谓“温热阳邪也,阳盛伤人之阴也”,“热病未有不耗阴者,其耗之未尽则生,尽则阳无留恋,必脱而死”。可见,慢性乙肝从发病初期到后期都有阴伤表现。对于治疗,吴鞠通强调“温热为法,法在救阴”,叶天士认为“留得一分阴液,便存得一分生机”。说明养阴法在慢性乙肝的治疗中占有重要地位。
补肾活血法治疗强直性脊柱炎研究现状

强直性脊柱炎(AS)是一种原因不明、以中轴关节慢性炎症为主的全身性疾病,晚期可造成髋关节和脊柱强直畸形,导致患者活动功能受限,严重影响患者的正常生活和工作。中医药在治疗AS方面发挥了良好的作用。目前,中医学者多认为肾虚血瘀是AS发病的根本病因病机,因此,以补肾活血为基础治疗AS已成为共识,大量的临床研究结果显示补肾活血法是治疗AS的有效之法,而基础实验研究的不断开展,也为补肾活血法治疗AS提供了有力的支持。笔者现将补肾活血法在AS治疗中的应用及研究现状综述如下。
《全国医疗服务价格项目规范》中西医项目技术难度和风险程度赋值对比性分析

目的:通过对《全国医疗服务价格项目规范》中中西医项目技术难度和风险程度赋值对比性分析,为将来物价部门和卫生行政部门对中医、西医项目制定价格提供参考。方法对2012年版《全国医疗服务价格项目规范》中中医项目与西医项目之间、中医各专业组之间的技术难度和风险程度赋值进行对比分析,发现其中的问题。结果中医与西医项目比较,中医项目技术难度和风险程度赋值偏低,二者基本处于一种倒置的状态,中医各专业组项目之间的赋值分布所占比例也未形成均衡分布。结论建议各地区政府主管部门合理测算项目的实际技术难度与风险程度,制定符合本地实际的中医医疗服务项目价格。
甲状旁腺癌一例报告

讨论甲状旁腺癌(parathyroid carcinoma)在我国较为罕见,绝大多数为功能性肿瘤,据国外统计,其占原发性甲状旁腺功能亢进(primary hyperparathyroidism)的比例不到1%。因其过度分泌PTH,临床表现为持续性的高钙血症及相关性损害,如骨质疏松、纤维囊性骨炎、病理性骨折、泌尿系结石等,故早期诊断困难且与良性原发性甲状旁腺功能亢进难以鉴别。因此,对复发性尿路结石、纤维囊性骨炎、病理性骨折患者常规行血钙和PTH 检测将有助于早期诊断。有研究认为,血钙>14 mg/ dl,PTH>5倍正常值,高血钙相关的颈部可及肿块或喉返神经麻痹其中任何1项可考虑甲状旁腺癌的诊断。
A review of bridge scour monitoring techniques

The high profile failure of the Malahide Viaduct in Dublin, Ireland, which is a part of the EU TEN-T network of critical transport links, was caused by foundation scour. Scour is a common soil-structure interaction problem. In light of current changes in climate, increasing frequency of flooding, coupled with the increasing magnitude of these flood events, will lead to a higher risk of bridge failure. Monitoring scour is of paramount importance to ensure the continued safe operation of the aging bridge asset network. Most monitoring regimes are based on expensive underwater instrumentation that can often be subjected to damage during times of flooding, when scour risk is at its highest. This paper presents a critical review of existing scour monitoring equipments and methodologies with a particular focus on those using the dynamic response of the structure to indicate the existence and severity of the scour phenomenon affecting the structure. A sensitivity study on a recently developed monitoring method is also undertaken.
Effects of hydraulic retention time, temperature, and effluent recycling on efficiency of anaerobic filter in treating rural domestic wastewater

With rural population expansion and improvement of the socio-economic standard of living, treatment of rural domestic wastewater has rapidly become a major aspect of environmental concern. Selection of a suitable method for treatment of rural domestic wastewater depends on its efficiency, simplicity, and cost-effectiveness. This study investigated the effects of hydraulic retention time (HRT), temperature, and effluent recycling on the treatment efficiency of an anaerobic filter (AF) reactor. The first round of experimental operations was run for three months with HRTs of one, two, and three days, temperatures of 18℃, 21℃, and 24℃, and no effluent recycling. The second round of experimental operations was conducted for another three months with HRTs of three and four days; temperatures of 30.67℃, 30.57℃, and 26.91℃; and three effluent recycling ratios of 1:1, 1:2, and 2:1. The first round of operations showed removal rates of 32% to 44% for COD, 30% to 35% for TN, 32% to 36% for NH_4~+ -N, 19% to 23% for NO_3~? -N, and 12% to 22% for TP. In the second round of operations, the removal rates varied from 75% to 81% for COD, 35% to 41% for TN, 31% to 39% for NH_4~+ -N, 30% to 34% for NO_3~? -N, and 41% to 48% for TP. The average gas production rates were 6.72 L/d and 7.26 L/d for the first and second rounds of operations, respectively. The gas production rate increased in the second round of operations as a result of applied effluent recycling. The best removal efficiency was obtained for an optimum HRT of three days, a temperature of 30℃, and an effluent recycling ratio of 2:1. The results show that the removal efficiency of the AF reactor was affected by HRT, temperature, and effluent recycling.
Effect of upward seepage on bedload transport rate

The paper presents an investigation of injection effects on the bedload transport rate. According to dimensional analysis, two dimensionless groups, an Einstein’s parameter group and a modified densimetric Froude number group, were chosen to examine how injection affects the bedload transport rate. Experimental studies were conducted in an open-channel flume with an upward seepage zone. The sediment particles used for the test were 0.9 mm in diameter. The experimental results show that an increase in the injection velocity causes a reduction in the shear velocity excess, which is defined as the difference between the shear and critical shear velocities, leading to a reduction in the bedload transport rate. The equation for predicting the bedload transport rate in the presence of upward seepage was derived empirically. The proposed prediction method is suitable for engineering practice, since it only requires the undisturbed flow condition, properties of sediment particles, and the injection velocity.
Detention basins as best management practices for water quality control in an arid region

Flood control detention basins (DBs) can act as water quality control structures or best management practices (BMPs). A key pollutant that DBs serve to settle out is particulate phosphorus, which adsorbs onto sediment. This study examines the sediment phosphorus concentration and its relationship with the particle size of sediment microcosms from pre- and post-rain event samples obtained from six DBs located in Clark County, Nevada. DBs were allotted a land use classification to determine if there was a correlation between the sediment phosphorus concentration and surrounding land use. The curve number method was used to calculate the runoff and subsequent phosphorus carried into the DB by the runoff. Our data show sediment phosphorus concentrations to be highest in soils from undeveloped areas. Runoff amount also plays a substantial role in determining the amount of phosphorus brought into the DB by sediment. This research has implications for improvement of water quality in arid regions.
High-power terahertz pulse sensor with overmoded structure

Based on the hot electron effect in a semiconductor, an overmoded resistive sensor for 0.3-0.4 THz band is investigated. The distribution of electromagnetic field components, voltage standing wave ratio (VSWR), and the average electric field in the silicon block are obtained by using the three-dimensional finite-difference time-domain (FDTD) method. By adjusting several factors (such as the length, width, height and specific resistance of the silicon block) a novel sensor with optimal structural parameters that can be used as a power measurement device for high power terahertz pulse directly is proposed. The results show that the sensor has a relative sensitivity of about 0.24 kW~(-1), with a fluctuation of relative sensitivity of no more than ±22%, and the maximum of VSWR is 2.74 for 0.3-0.4 THz band.
Performance of a double sided silicon strip detector as a transmission detector for heavy ions

The performance of a double sided silicon strip detector (DSSSD), whicn is used for the position and energy detection of heavy ions, is reported. The analysis shows that although the incomplete charge collection (ICC) and charge sharing (CS) effects of the DSSSD give rise to a loss of energy resolution, the position information is recorded without ambiguity. Representations of ICC/CS events in the energy spectra are shown and their origins are confirmed by correlation analysis of the spectra from both the junction side and ohmic side of the DSSSD.
Multi-polar resistance switching and memory effect in copper phthalocyanine junctions

Copper phthalocyanine junctions, fabricated by magnetron sputtering and evaporating methods, show multi-polar (unipolar and bipolar) resistance switching and the memory effect. The multi-polar resistance switching has not been observed simultaneously in one organic material before. With both electrodes being cobalt, the unipolar resistance switching is universal. The high resistance state is switched to the low resistance state when the bias reaches the set voltage. Generally, the set voltage increases with the thickness of copper phthalocyanine and decreases with increasing dwell time of bias. Moreover, the low resistance state could be switched to the high resistance state by absorbing the phonon energy. The stability of the low resistance state could be tuned by different electrodes. In Au/copper phthalocyanine/Co system, the low resistance state is far more stable, and the bipolar resistance switching is found. Temperature dependence of electrical transport measurements demonstrates that there are no obvious differences in the electrical transport mechanism before and after the resistance switching. They fit quite well with Mott variable range hopping theory. The effect of Al_2O_3 on the resistance switching is excluded by control experiments. The holes trapping and detrapping in copper phthalocyanine layer are responsible for the resistance switching, and the interfacial effect between electrodes and copper phthalocyanine layer affects the memory effect.
Photoluminescence properties and energy transfer in Y_2O_3:Eu~(3+) nanophosphors

The photoluminescence (PL) properties of Y_2O_3:Eu~(3+) nanophosphors were systematically investigated with the goal of improving the color quality and quantum efficiency of Y_2O_3:Eu~(3+) nanophosphors for potential applications in nanoscale devices. The emission spectra, excitation spectra and fluorescence decay curves were employed to trace the energy transfer process from Eu~(3+) at C_(3i) site to Eu~(3+) at C_2 site. The experimental results show that the energy transfer process becomes more and more efficient with the increase in the Eu~(3+) concentration. The emission of Eu~(3+) at C2 site is favorable because it has high radiative efficiency and better color quality. The successful suppress of the emission Eu~(3+) at C_(3i) is especially important for its applications in general illumination or display technology. The quantum efficiency and color quality of Y_2O_3:Eu~(3+) can be improved by controlling the energy transfer between the Eu~(3+) at S6 site and Eu~(3+) at C_2 site.
Structural and photoluminescence properties of terbium-doped zinc oxide nanoparticles

We present in this paper a study of the structural and photoluminescence (PL) properties of terbium (Tb) doped zinc oxide (ZnO) nanoparticles synthesized by a simple low temperature chemical precipitation method, using zinc acetate and terbium nitrate in an isopropanol medium with diethanolamine (DEA) as the capping agent at 60 °C. The as-prepared samples were heat treated and the PL of the annealed samples were studied. The prepared nanoparticles were characterized with X-ray diffraction (XRD). The XRD patterns show the pattern of typical ZnO nanoparticles and correspond with the standard XRD pattern given by JCPDS card No. 36-1451, showing the hexagonal phase structure. The PL intensity was enhanced due to Tb~(3+) doping, and it decreased at higher concentrations of Tb~(3+) doping after reaching a certain optimum concentration. The PL spectra of Tb~(3+) doped samples exhibited blue, bluish green, and green emissions at 460 nm (~5D_3 - ~7F_3), 484 nm (~5D_4 - ~7F_6), and 530 nm (~5D_4 - ~7F_5), respectively, which were more intense than the emissions for the undoped ZnO sample. Based on the results, an energy level schematic diagram was proposed to explain the possible electron transition processes.
A novel 2-μm pulsed fiber laser based on a supercontinuum source and its application to mid-infrared supercontinuum generation

A new method to achieve 2-μm pulsed fiber lasers based on a supercontinuum (SC) is demonstrated. The incident pump light is a pulsed SC which contains a pump light and a signal light at the same time. The initial signal of the seed laser is provided by the incident pump light and amplified in the cavity. Based on this, we obtain a 2-μm pulsed laser with pulse repetition rate of 50 kHz and pulse width of 2 ns from the Tm-doped fiber laser. This 2-μm pulsed laser is amplified by two stages of fiber amplifiers, then the amplified laser is used for mid-infrared (mid-IR) SC generation in a 10-m length of ZrF_4-BaF_2-LaF_3-AlF_3-NaF (ZBLAN) fiber. An all-fiber-integrated mid-IR SC with spectrum ranging from 1.8 μm to 4.3 μm is achieved. The maximal average output power of the mid-IR SC from the ZBLAN fiber is 1.24W(average output power beyond 2.5 μm is 340 mW), corresponding to an output efficiency of 6.6% with respect to the 790-nm pump power.
CFD simulation on the gasification of asphalt water slurry in an entrained flow gasifier

Gasification technology is suggested to utilize asphalt particles, which are produced in the heavy oil deep separation process of using coupled low temperature separation of solvent and post extraction residue. In this work, the asphalt particles were first slurried with water and then gasified to produce synthesis gas. The gasification process of asphalt water slurry in an entrained flow gasifier was simulated using a three-dimensional computational fluid dynamics (CFD) model based on an EulerianLagrangian method. The trajectories and residence time of asphalt particles, and the reaction rates, gas species distribution, temperature field and carbon conversion in the entrained flow gasifier were obtained. The predicted results indicated that the asphalt water slurry was a good feedstock for gasification. Moreover, the effects of particle size,oxygen equivalence ratio, and mass content of asphalt particles on the gasification performance of asphalt water slurry were investigated. These results are helpful for industrial application of asphalt water slurry gasification technology.
环丙沙星-镉复合污染对高低累积型菜心种子发芽的影响

抗生素被大量用于人类医疗及动物养殖中,大部分以原形排出并进入环境。针对珠三角地区抗生素污染特征的研究结果表明,土壤及地表水中均有多种抗生素被检出,以喹诺酮类抗生素为主,其含量在1.0~5080.1 ng·L~(-1)(水)以及0.03~1.53 mg·kg~(-1)(土壤)之间。同时,珠三角地区土壤中Cd 等重金属污染较为严重,土壤中Cd 含量在0.57~11.0 mg·kg~(-1)之间。目前针对重金属或抗生素单一污染毒性效应的研究均有报道,但关于二者复合污染毒性效应的研究还鲜见报道。菜心是珠三角地区常年种植的主要蔬菜,品种多达数十种。油青四九菜心和油绿粗苔菜心是前期筛选的环丙沙星(CIP)高累积和低累积菜心品种,在环丙沙星污染条件下,前者的累积量为后者的3~10倍。本文主要研究在 CIP 及 Cd 单一及其复合污染下对两种菜心的毒性效应。
A seismic texture coherence algorithm and its application

The first generation coherence algorithm (the CI algorithm) that calculates the coherence of seismic data in-line and cross-line was developed using statistical cross-correlation theory, and it has the limitation that the technique can only be applied to horizons. Based on the texture technique, the texture coherence algorithm uses seismic information in different directions and differences among multiple traces. It can not only calculate seismic coherence in in-line and cross-line directions but also in all other directions. In this study, we suggested first an optimization method and a criterion for constructing the gray level co-occurrence matrix of the seismic texture coherence algorithm. Then the co-occurrence matrix was prepared to evaluate differences among multiple traces. Compared with the Cl algorithm, the seismic texture coherence algorithm suggested in this paper is better than the Cl in its information extraction and application. Furthermore, it implements the multi-direction information fusion and it, also has the advantage of simplicity and effectiveness, and improves the resolution of the seismic profile. Application of the method to field data shows that the texture coherence attribute is superior to that of Cl and that it has merits in identification of faults and channels.
Oil maturity assessment using maturity indicators based on methylated dibenzothiophenes

Aromatic fractions of 140 oils and condensates that originated from different types of source rocks (marine shale, terrestrial shale and marine carbonate) were analyzed using gas chromatographymass spectrometry (GC-MS) to investigate the relative distributions of methylated dibenzothiophenes with respect to thermal maturity. The positions of methyl groups of trimethyldibenzothiophene isomers (TMDBTs) including those used in the definition of maturity indicator TMDBT index in previous studies were firmly identified by co-elution of internal standards in GC-MS analysis and by comparing with reported retention indices. A new maturity ratio related to dimethyldibenzothiophenes (DMDBTs) is proposed on the basis of the differences in thermodynamic stability among different DMDBT isomers. Another maturity index (TMDBT-I2) based on TMDBTs is also suggested on the basis of our empirical observations and presumed thermodynamic stability of TMDBT isomers. These two newly proposed (2,6 + 3,6)-/l,4-DMDBT ratio and TMDBT-I2 correlate well with MDR (4-/1-methyldibenzothiophene) and 2,4-/l,4-DMDBT ratios, suggesting their common chemical reaction mechanisms and similar behavior with increasing maturity. Therefore, they can be effectively applied for maturity assessments. Furthermore, the TMDBTs related maturity parameters are more reliable for over-mature oils and condensates due to the relatively higher concentrations of thermodynamically unstable TMDBT isomers, i.e. 1,4,6-, 1,4,8- and 3,4,6-TMDBT in this study than those of 1-methyldibenzothiophene (1-MDBT) or 1,4-DMDBT. In contrast with 4,6-/l,4-DMDBT, the newly proposed (2,6 + 3,6)-/l,4-DMDBT ratios for oils that originated from different types of source rocks have approximately same relationship with the oil maturity (R_c %). This suggests that the lithology and organic facies may have relatively less influence on (2,6 + 3,6)-/l,4-DMDBT ratio compared to 4,6-/1,4-DMDBT. The maturity parameters based on methylated dibenzothiophenes are particularly useful in the maturity assessments of post- and over-mature oils and condensates and can complement maturity indicators based on steranes and terpanes.
Sedimentary hydrodynamic study of sand bodies in the upper subsection of the 4th Member of the Paleogene Shahejie Formation in the eastern Dongying Depression, China

Petroleum is produced from a beach-bar sand reservoir in the upper subsection of the 4th member of the Paleogene Shahejie Formation (Es_4~s) in the eastern Dongying Depression, penetrated by many wells in the Guangli-Qingnan area and this subsection still has further exploration potential. Using drilling and logging data, we analyzed the sand body types, emphasizing the sedimentary characteristics of the beach-bar sand bodies. Combining these data with the concepts of lacustrine and oceanic hydrodynamics, we explain the formation and distribution of the beach-bar sands in the eastern Dongying Depression. The connectivity between beach-bar sand bodies within each individual hydrodynamic zone is better than that between sand bodies in any two adjacent zones. The tempestite sand bodies developed in this area are characterized by typical storm deposits and are located at the bottoms of the beachbar sand bodies. They grade upward to normal shore and shallow-lacustrine beaches and bars. We also propose a new simple method to estimate the paleo-water depth using the thicknesses of the bar sand bodies in parasequences combined with the principle of hydrodynamic zonation. Based on the distribution of the beach-bar sands in parasequence set 3,we infer that the paleo-wind direction was from the north with an average paleo-wind force of 6 when the major beach-bar sand bodies formed.
人β-防御素-2的研究进展

防御素(defensin)是一类相对分子质量为(4.0~5.0)× 10~3且富含氨基酸残基的阳离子抗菌肽。对革兰阴性菌、分枝杆菌、真菌等有很强的杀伤活性,在哺乳动物固有免疫中起着重要作用。人β-防御素-2(humanβ-defensin-2,HBD-2)是人体中第一个被发现的可诱导性表达的防御素,主要来源于皮肤角质细胞、黏膜上皮细胞,在皮肤、黏膜的固有免疫功能中具有重要作用。对细菌、真菌、病毒等微生物均有很强的杀伤活性。与多种疾病的免疫病理机制密切相关。迄今为止,在人体内已发现了α、β两类防御素。其中β防御素家族共有6种亚型, HBD1~6。HBD-2首次发现于牛皮癣患者皮损角质细胞,正常情况下机体HBD-2的表达水平很低,当受到促炎症细胞因子和微生物等刺激后,在其表达迅速上调。本文对HBD-2的研究进展进行综述。
早产极低出生体质量儿3种鼻饲喂养方式的效果观察

早产极低出生体质量儿(very low birth weight infant,VLBWI)因胎龄小、消化系统发育不成熟,在喂养时极易发生喂养不耐受。而且由于胃肠功能成熟程度存在较大差异,在制订 VLBWI的胃肠道内喂养方案时,临床医生要考虑到胎龄、出生体质量、生命体征,以及是否存在感染等诸多因素。因此,胃肠喂养对VLBWI的生长发育非常重要,开始喂养日龄、喂养方式、选择合适的乳类等可以提高VLBWI的存活率和存活质量,但仍有很多有待解决的问题。为改善VLBWI胃肠喂养的耐受性,使其顺利渡过喂养关,尽快过渡到自行吸奶,需制订合适的喂养方法。近年来,临床研究发现间歇持续鼻饲输注喂养有利于刺激胃肠激素释放和促进更完全的胃排空,促进 VLBWI生长发育和胃肠功能完善。本文选择2008年1月至2012年9月本院胎龄小于34周的VLBWI 65例,对其喂养过程中恢复出生体质量时间、喂养不耐受情况、黄疸持续时间、胃管留置及平均住院时间进行观察分析,现报道如下。