香青藤的生药鉴定

利用药材性状、显微特征、紫外吸收光谱和薄层层析等鉴别方法对香青藤进行生药鉴定研究 ,为该药材的鉴别和开发利用提供科学依据     

Increasing fire and the decline of fire adapted black spruce in the boreal forest

Intensifying wildfire activity and climate change can drive rapid forest compositional shifts. In boreal North America, black spruce shapes forest flammability and depends on fire for regeneration. This relationship has helped black spruce maintain its dominance through much of the Holocene. However, with climate change and more frequent and severe fires, shifts away from black spruce dominance to broadleaf or pine species are emerging, with implications for ecosystem functions including carbon sequestration, water and energy fluxes, and wildlife habitat. Here, we predict that such reductions in black spruce after fire may already be widespread given current trends in climate and fire. To test this, we synthesize data from 1,538 field sites across boreal North America to evaluate compositional changes in tree species following 58 recent fires (1989 to 2014). While black spruce was resilient following most fires (62%), loss of resilience was common, and spruce regeneration failed completely in 18% of 1,140 black spruce sites. In contrast, postfire regeneration never failed in forests dominated by jack pine, which also possesses an aerial seed bank, or broad-leaved trees. More complete combustion of the soil organic layer, which often occurs in better-drained landscape positions and in dryer duff, promoted compositional changes throughout boreal North America. Forests in western North America, however, were more vulnerable to change due to greater long-term climate moisture deficits. While we find considerable remaining resilience in black spruce forests, predicted increases in climate moisture deficits and fire activity will erode this resilience, pushing the system toward a tipping point that has not been crossed in several thousand years.

Disturbances can be powerful catalysts of state changes in ecosystems, first by disrupting the inertia that site occupancy confers on long-lived, sessile organisms like trees and second by affecting the biophysical conditions that influence patterns of vegetation recovery (1). Disturbances may be particularly disruptive when they depart from the historical regimes experienced by an ecosystem, altering postdisturbance regeneration outcomes and stimulating rapid reorganization of the system into a new ecological state, often referred to as a loss of resilience (2, 3). In boreal North America, climate change is leading to warmer, drier conditions with more lightning strikes in many regions (4), altering fire activity (5, 6) and modifying postfire regeneration conditions. These changes affect which species’ traits promote successful postfire recruitment and may disrupt forest regeneration entirely, creating substantial uncertainty in the prediction of future forest composition (1, 7). Forecasting changes in boreal forest composition is further complicated by regional differences that shape the local biophysical context (e.g., species pools, soil organic layer thickness, and climate). To date, large-scale patterns in regeneration dynamics have been precluded by the vastness of the boreal biome and lack of biome-wide recruitment information.Currently, much of boreal North America is dominated by evergreen conifers, most notably, black spruce (Picea mariana), which over the Holocene has repeatedly self-replaced via seedling establishment from aerial seedbanks, demonstrating the high resilience of this species to stand-replacing fire (8–10). In this region, where fires typically occur at intervals shorter than the life span of the postfire cohort of trees (i.e., <100 to 150 y) (8, 11), initial patterns of tree regeneration and relative growth rates determine the trajectory of future forest composition until the next fire (12, 13). Consequently, seedling recruitment in the initial years after fire is the critical determinant of mature forest stand composition for boreal tree species (8, 9, 12, 14, 15). Recent studies have indicated that fires of unusually high severity and/or short return intervals can disrupt the successful regeneration strategy of black spruce, stimulating shifts to alternative states dominated by deciduous broadleaf trees or jack pine (Pinus banksiana) (16–18) or even nonforest (19, 20), changes indicative of reduced black spruce resilience. As a dominant species, large areas of the North American boreal forest are shaped by the flammability of black spruce (21) and also its role in creating wildlife habitat for important species, such as caribou (22), and supporting the sequestration of large quantities of belowground carbon (23) while being one of the most economically important boreal tree species (24); as such, reduced recovery of black spruce forest postfire has wide-ranging implications.Fire can trigger state changes away from black spruce dominance, and although we do not know how common these changes are, rapid rates of warming and fire activity intensification in boreal North America would suggest that such state changes are already widespread. Previous research has shown that black spruce self-replacement is supported in sites where thicker soil organic layers persist following fire (16, 25), whereas shortening fire return intervals and postfire drought conditions may undermine regeneration processes (19, 20). Indeed, complete regeneration failure has been observed at 9% of sites experiencing short-interval fires simply because reproductive maturity was not yet attained (26). Given these findings, we expected widespread reductions in black spruce resilience and that previously demonstrated drivers of population dynamics (e.g., residual soil organic layer thickness and fire return interval) would be consistently important at the continental scale. However, we also expected regional differences in the frequency of state changes given climatic gradients from east to west that may affect burning (5) and/or create more stressful regeneration conditions (19) leading to more frequent loss of resilience and the most extreme manifestation—a complete absence of recruitment—in the drier, western regions of boreal North America.To test these predictions, we conducted a continent-wide examination of regeneration success by synthesizing field data from wildfires that occurred between 1989 and 2014 (SI Appendix, Table S1) across boreal North America [637 million ha of forested land and 37% of the boreal biome (27)]. We compared prefire tree species composition and relative density with postfire establishment of tree seedlings (measured from 2 to 13 y following fire, depending on the study). This recruitment window measures an initial cohort of trees that grow to dominate the canopy (13), providing a good predictor of forest composition during proceeding decades (12, 15) and the one to two centuries that follow (13, 28). Most sites were dominated by conifers before fire (1,400 of 1,538 sites; 91%), and more specifically by black spruce (1,140 sites; 74%), approximating the proportion of forest types that burn in boreal North America (21) (SI Appendix, Table S1). We define resilience as the ability of a stand to quickly recover its basic structure and function following disturbance (29) and expect that recent changes in climate and fire activity may have altered regeneration conditions sufficiently to erode resilience to varying degrees following fire, ranging from loss of dominance to regeneration failure. To address this, we evaluated the frequency of losses of conifer resilience (i.e., conifer regeneration failure or a shift toward broadleaf dominance) and black spruce resilience (i.e., black spruce regeneration failure or a shift toward broadleaf or pine dominance) using a postfire trajectory metric based on changes in stem density and species dominance (Fig. 1; see Materials and Methods). We considered two groups: dominant (locally most common) and subordinate (locally less common) species in the canopy at the time of burning (Fig. 1). For dominants, we evaluated forest responses in two ways: all conifers combined (to evaluate the conifer-to-broadleaf transition) or black spruce only (to evaluate changes in this historically dominant species). For prefire dominants, postfire regeneration could lead to two resilient outcomes (Fig. 1A): self-replacement or density reduction; in both, relative dominance is maintained or increased but absolute density responses differ. Three outcomes associated with loss of dominance reflect decreasing postfire resilience: competition (absolute density of prefire dominant is maintained or increased concurrent with strong recruitment of other taxa; regeneration outcome is dictated by relative competitive abilities), poor establishment (decreased absolute density), or regeneration failure (postfire density of the prefire dominant is zero). For common prefire subordinate taxa, we again evaluated forest response in two ways: broadleaf taxa combined (to evaluate the potential for broadleaf taxa to replace conifers postfire) and jack pine only (to evaluate conifer-to-conifer transitions between black spruce and jack pine). For prefire subordinates, expansion and competition categories indicate reduced resilience of the prefire dominant (conifer or black spruce) (Fig. 1B).Open in a separate windowFig. 1.A framework to evaluate the potential for state changes following fire. A represents possible trajectories for Species A, a prefire dominant taxon (Species A comprises ≥50% of prefire stem density). Resilience is the most likely outcome in the self-replacement panel, in which the prefire dominant taxon continues to dominate after fire and sufficient seedlings have established to at least maintain, or possibly increase, species-specific prefire stem densities; density reduction was also considered to be a more stable or resilient outcome than the other outcomes. We considered that the competition, poor establishment, and regeneration failure categories would all likely lead to state change. B represents possible trajectories for Species B, a prefire subordinate taxon (Species B comprises <50% stem density), and we were interested in understanding the potential for expansion (i.e., postfire increase in dominance and maintenance or increase in stem density) of Species B. In this case, postfire state change (i.e., loss of resilience of the prefire dominant) is most likely in the expansion category. However, in our study, given the greater competitive abilities of the prefire subordinates in question (i.e., broadleaf taxa and jack pine) compared to black spruce (the most common prefire dominant in our dataset), the competition category will also like lead to loss of resilience when the prefire dominant is black spruce. Poor establishment and density reduction categories in B were never observed in our dataset. In boreal North America, fires typically occur at intervals shorter than the lifespan of the postfire cohort of trees (<100 y); therefore, the pulse of seedling establishment immediately postfire typically determines the trajectory of future forest composition until the next fire.We used this framework to address two questions: 1) How often does the prefire dominant species show decreased resilience (i.e., ecological state change) to recent fires in boreal North America? and 2) Is the magnitude and direction of change consistent among regions? Finally, to address whether there are consistent drivers across boreal North America that promote postfire ecological state change, we assessed several factors related to fire and seedbed conditions considered important in determining the postfire regeneration outcomes outlined in Fig. 1. Evidence of common drivers suggests the intensification of wildfire activity will affect boreal North America in predictable ways.     

Nut Allergy: Clinical and Allergological Features in Italian Children

Background: Nut allergies are an increasingly frequent health issue in the pediatric population. Tree nuts (TN) and peanuts are the second cause of food anaphylaxis in Italy. Unfortunately, knowledge of the clinical characteristics of a TN allergy in Italian children is limited. Our study aimed to identify the clinical and allergological characteristics of Italian children with a nut allergy (TN and peanut). Methods: A retrospective observational analysis was performed on the clinical charts of children with a history of nut reaction referred to the allergy unit of the hospital from 2015 to 2019. The studied population was represented by children with a confirmed nut allergy based on positive prick by prick and/or serum-specific IgE to nut plus a positive nut oral food challenge. Demographic, clinical, and allergological features were studied and compared among different nuts. Results: In total, 318 clinical charts were reviewed. Nut allergy was confirmed in 113 patients. Most patients (85/113, 75%) had a familial history of allergy and/or a concomitant allergic disorder (77/113, 68%). Hazelnut and walnut were the more common culprit nuts observed in allergic children. Anaphylaxis was the first clinical manifestation of nut allergy in a high percentage of children (54/113, 48%). The mean age of the first nut reaction was statistically higher with pine nuts. Over 75% of children reported a single nut reaction. During the OFCs, the signs and symptoms involved mainly the gastrointestinal system (82/113, 73%) and resolved spontaneously in most cases. Severe reactions were not frequent (22/113, 19%). Conclusion: To our knowledge, this is the first Italian study that provided a comprehensive characterization of children with a nut allergy. These results are important for clinicians treating children with a nut allergy.     

自拟“黄芪淫羊藿汤”治疗慢性肾炎

目的：治疗慢性肾炎。方法：自拟“黄芪淫羊藿汤”治疗慢性肾炎。结果：经过半年治疗,病情明显好转。结论：从中医理论入手治疗慢性肾炎,从肺脾肾三藏入手,从而调节人体的平衡。     

应用携带指掌侧固有神经背侧支的指动脉逆行岛状皮瓣修复指端缺损

指端缺损包括指腹软组织、指骨、甲床及其支持结构。因其位于手指最远端,所以在手外伤中较常见。由于损伤的机制不同,损伤的类型也多种多样,且由于外观及结构的特殊性,对指端损伤修复的要求也很高。指端损伤的多样性决定了修复方法的多样性。主要有短缩直接缝合、游离植皮、皮辩转移、再植等多种方法,每种方法都有其最佳适应症及优缺点。笔者对2—5指指腹单纯软组织缺损、甲孤以远的复合组织缺损、侧方缺损,且无再植条件者,采用携带指掌侧固有神经背侧支的指动脉逆行岛状皮辩进行修复,从2005年-2009年共65倒70指,取得良好效果。     

正交实验法优化疏毛吴茱萸提取工艺

目的：优化疏毛吴茱萸提取工艺。方法：以疏毛吴茱萸提取物中吴茱萸碱和吴茱萸次碱的总量为指标,分别采用L9（34）正交试验法对疏毛吴茱萸水提、醇提工艺进行优选。结果：疏毛吴茱萸总碱水提的最佳工艺路线为：用10倍量水,回流提取3次,每次2小时。醇提的最佳工艺路线为：用6倍量60%的乙醇,回流提取3次,每次2小时。结论：两种提取工艺简单可行,可提供质量均一稳定的疏毛吴茱萸提取物。     

射干麻黄汤治疗咳喘病(寒饮郁肺型)疗效观察

[目的]观察射干麻黄汤治疗寒饮郁肺型咳喘病疗效。[方法]观察73例,中药治疗组49例,口服射干麻黄汤,每日1剂,早晚各1次温服。对照组24例,给予头孢克肟0.1,每日2次,病毒感染为主者,加用利巴韦林0.3/次,甘草合剂10mL/次,1日3次。[结果]中药治疗组49例,痊愈18例,显效17例,有效11例,无效4例。对照组24例,痊愈3例,显效4例,有效4例,无效13例。[结论]治疗组痊愈率、显效率明显优于对照组。     

广西九里香挥发油GC-MS研究

目的:对广西原产地的广西九里香挥发油进行气相-质谱研究。方法:水蒸气蒸馏法提取广西九里香挥发油,气相色谱-质谱联用(GC-MS)法鉴定化学成分,归一化法测定各成分相对含量。结果:从广西九里香挥发油中共分离出50多个组分,鉴定了其中36个化合物,占总量的90%以上,主要成分为香叶醛(Geranial,19.33%)、橙花醛(Neral,17.26%)、乙酸香叶酯(Geranyl acetate,11.27%)、香茅醛(Citronellal,11.12%)等。结论:广西九里香挥发油中含萜类、醛类、烃类等多种化学成分,本实验为广西九里香的进一步开发利用提供了科学依据。     

Repair of tracheal defect with Goretex graft during resection of carcinoma of the esophagus

Repair options for tracheal defects secondary to tumor or trauma have been unsatisfactory for emergent cases. We report a case in which the tracheobronchial tree was entered during resection of carcinoma of the esophagus and emergently repaired with a Goretex graft. The patient did well for 22 months after esophagectomy, at which time the graft was found to be infected and was removed. The patient continues to remain free of tumor 4 years after initial resection. J. Surg. Oncol. 1997;66:134–137. © 1997 Wiley-Liss, Inc.     

基于决策树模型HC25病组DRGs细分组及住院费用的影响因素研究

目的 构建基于决策树模型HC25病组患者DRGs细分组的研究及住院费用的影响因素。方法 收集西安交通大学第一附属医院2020年1月至2022年6月依据CHS-DRG分组方案进入HC25(胆囊切除术,不伴并发症或合并症)病组患者的病案首页数据(n=3 844),通过单因素和多因素分析了解影响住院费用的主要因素,通过建立决策树模型进行病例组合,分析分组效果及不同分组的费用标准。结果 正态性检验结果显示:住院费用呈偏态分布(χ²=0.197,P<0.001);单因素方差分析结果显示:住院费用在不同年龄、性别、手术方式、患者来源、医疗付费方式、入院病情危重情况、术前时间、住院时间、是否有再住院计划之间,差异有统计学意义(P均<0.05);多重线性逐步回归分析结果显示,影响住院费用显著性差异的因素从大到小依次为:住院时间、手术方式、入院病情危重情况、性别、术前时间、患者来源、再住院计划(P均<0.05);采用CHAID共生成了7个DRGs分组,第一层分类节点变量是手术方式,第二层是术前时间、住院时间,第三层是入院时病情危重情况;不同DRGs组合的住院费用比较,差异有统计学意义(χ²=2 474.595,P<0.001),组合DRGs(1)的住院费用最高,权重最高;DRGs(7)的住院费用最低,权重最小;所有DRGs病组中超标费用患者共170例(4.42%),各组超标费用比例均<10%。结论 基于决策树模型对HC25病组的细分组效果合理有效,能较客观反映医疗资源消耗水平。