新疆吐鲁番加依墓地的母婴合葬现象

新疆吐鲁番加依墓地位于吐鲁番市亚尔乡加依村南3公里的戈壁台地上,其年代大致在青铜-早期铁器时代。本文结合人类骨骼考古学、死亡考古学与临床医学的方法,对其中4例疑似的母婴合葬墓（M31、M70、M222、M224）进行了研究。通过对墓葬中遗骸的生物学信息以及埋藏位置信息的采集与分析,判断这4座墓葬中的个体关系应当为母亲和其婴儿。其中,3座墓葬中的母婴个体为分娩后死亡,1座墓葬中的母亲和胎儿个体死于孕期或者分娩过程中。造成这些个体死亡的直接原因可能是难产和产褥期疾病,营养不良和感染性疾病等因素也增加了他们的死亡风险。这4座墓葬一方面体现了古代女性生育所面临的困难,一方面体现了加依先民们对于母婴联结以及“灵魂”的认识,将母婴葬于一室不仅是对死者的关怀,更是对生者的告慰。本文的研究旨在为解读古代遗址中的母婴合葬墓提供一个新视角。     

围小丛壳Glomerella cingulata子囊孢子交配繁殖、生物学特性及致病性

炭疽叶枯病（Glomerella leaf spot）是我国苹果上新发现的一种病害。为了解围小丛壳Glomerella cingulata子囊孢子的交配方式、生物学特性和致病性,从安徽砀山、山东牟平等地采集病害样品,经分离培养和纯化获得单孢菌株。在适宜条件下单孢菌株可产生子囊和子囊孢子,经过毛细管破子囊壁后单孢分离,获得12个子囊,每个子囊有8个子囊孢子。其中10个子囊中有4个“正”孢子（+）和4个“负”孢子（-）,2个子囊中只有“负”孢子。子囊孢子单孢菌株培养72h,“正”菌株菌落白色,以营养生长为主;“负”菌株菌落灰白色,直径略小于正菌株,菌丝稀疏,边缘菌丝白色,中部有大量橙色的分生孢子堆。“正”、“负”菌株异宗配合后,可产生大量可育子囊壳;单独的“正”菌株有性生殖产生稀疏丛簇状的可育子囊壳;单个的“负”菌株只能产生分散且不育的子囊壳。“正”、“负”菌株菌落的生长速度没有差异,对温度、营养、光照和pH值的敏感性也没有差异,但“正”、“负”菌株的致病性存在差异。正菌株的有性生殖没有导致rDNA-ITS、β-tubulin基因碱基序列变异。     

中国与“一带一路”参与国家抗击新冠肺炎疫情的国际科技合作现状与展望

2019年底暴发并席卷全球的新型冠状病毒肺炎疫情已经成为需要世界各国共同努力克服的全球重大卫生安全挑战。当前,中国已基本控制国内新冠肺炎疫情,并在疫情相关科学研究及公共卫生产品研发方面取得重大进展,同时加强了与“一带一路”参与国家开展国际科技合作。对中国与“一带一路”参与国家抗击新冠肺炎疫情的基础研究合作、国际科技合作项目等方面进行梳理,可以看到:中国与“一带一路”参与国家形成了领域交叉、节点多样的复杂合作网络,并主要与东南亚、中东欧和西亚各国合作密切;中国与“一带一路”参与国家的科研机构已在防控、流行病学和治疗等领域展开了大量实质研究,合作关系更偏向援助型合作。未来应加强与“一带一路”参与国家的生物技术产业合作与技术转移,发挥“一带一路”区域支点国家的示范效应等方面构建与“一带一路”参与国家更丰富、紧密、务实的科技合作关系。     

我国“干细胞及转化研究”重点专项的组织实施及思考

“十三五”期间,我国设立了国家重点研发计划“干细胞及转化研究”重点专项(以下简称“专项”)。通过五年实施,专项取得了显著进展。通过对专项立项和实施情况的回顾,总结管理中的经验和不足,为“十四五”干细胞研究部署提出相关建议,以进一步增强我国干细胞及转化研究的核心竞争力,加快推进干细胞研究成果惠及人民健康。     

本科遗传学教学中的遗传漂变概念探讨

遗传漂变是遗传学教学的难点之一,因其涉及随机性和概率,特别容易引起误解。定义中的“抽样误差”常被误解为遗传漂变是由于“抽样”这一研究方法干扰才导致基因频率的随机变化。本文首先对国内外《遗传学》教材中的遗传漂变定义进行了分析比较,发现“抽样误差”的定义为各教材普遍采用,但只有少数教材对“抽样误差”概念进行了正确的解释,多数未作进一步的说明。文章介绍了遗传漂变的研究历史,亦即Wright、 Fisher和Kimura等学者对遗传漂变研究的贡献。进而,特别介绍了近年来国外关于本科生遗传漂变教学的两篇代表性教学研究论文,指出本科生在学习过程中容易出现错误理解是难以避免的现象,对此也提供了初步的解决办法。作者最后结合自己的教学实践,提出本科生教学中遗传漂变仍然采用含有“抽样误差”概念的定义,只是需要对“抽样误差”做进一步的解释,指出“抽样误差”是等位基因世代传递过程中存在的、配子间的随机结合,“相当于”对整个参与交配的配子库中的配子进行的一次“随机抽样”,而与一般遗传学研究中的人为抽样行为无关。本文旨在为本科遗传学教学中关于遗传源变概念的讲解提供借鉴和参考。     

周口店直立人头骨创伤与人工切割痕迹辨析

自20世纪40年代魏敦瑞提出北京猿人（周口店直立人）可能存在“暴力争斗”和“同类残食”的观点之后,引发了一些学者和科普大众对北京猿人是否为“食人族”的争论。由于原始化石标本在第二次世界大战期间丢失,本文以保存下来的周口店（ZKD）直立人头骨原始模型和素描图为研究材料,对魏敦瑞提出的具有创伤和人工切割痕迹的5件标本（ZKD II、ZKD VI、ZKD X、ZKD XI和ZKD XII）进行辨析。结果显示：1）ZKD X、ZKD XI、ZKD XII这3件标本的头盖部,有7处可以确定为生前遭受非致死性撞击导致的局部创伤;2）ZKD VI头盖骨残片周边的及中央区域的断痕,为个体生前遭受致死性的暴力打击导致;3）ZKD II和ZKD VI顶骨位置疑似人工切割痕迹的沟槽实际上是动物啃咬或自然因素导致的,北京猿人“同类残食”的观点在本文研究中没有得到证实。北京猿人头骨的创伤痕迹都位于头盖部,以顶骨居多,其次为额骨,符合人群之间暴力冲突产生创伤的位置。     

碳中和的生态学透视

在简述碳中和概念的基础上, 重点对碳中和的实现途径及生态系统碳汇的重要性进行了评述, 认为碳减排和碳增汇是实现“碳中和”的两个决定因素; 碳减排的核心是节能、调结构、增效和发展清洁能源, 碳增汇的核心是生态保护、建设和管理。由于植被自然生长和生态建设等因素, 中国陆地生态系统发挥了, 并将在未来继续发挥着重要的碳汇作用。为增强生态系统的固碳能力, 作者提出“三优”生态建设和管理原则, 即“最优的生态系统布局、最优的物种配置、最优的生态系统管理”。此外, 文章还对“后碳中和”时代可能出现的问题和挑战进行了展望, 认为碳中和后, 由于气候变化, 特别是大气CO₂浓度增速减缓甚至下降等因素, 可能导致全球性的植被生产力下降, 对此可能带来的新的环境问题需要提前谋划和应对。     

基于报告基因敲入构建果生刺盘孢细胞核荧光标记菌株

运用基因敲入技术,将GFP、mCherry整合到果生刺盘孢 Colletotrichum fructicola组蛋白histone H1位点,实现融合表达,获得细胞核荧光标记菌株。基于标记菌株可以对分生孢子、营养菌丝、附着胞、侵染菌丝等结构中的细胞核进行实时活体观察。果生刺盘孢存在性亲和的“+”、“-”型菌株分化,GFP“+”型菌株和mCherry“-”型菌株接触形成明显杂交线,杂交线上单子囊内含红绿两种孢子,表明“+”、“-”型菌株间发生杂交;杂交线上子囊壳壁表达mCherry,表明由“-”型菌株发育而来。本研究构建的核荧光标记菌株将是研究果生炭疽菌细胞周期调控和有性繁殖过程的重要材料。     

数据科学在旧石器考古学中的应用

从考古学诞生之初,对抽象数据的解读与分析就一直伴随。对于旧石器考古学而言,“人工制品”成为了传达史前物质文化信息的主要载体,对人工制品中所提取的数据进行科学解读,成为了复原古代人类历史的关键步骤。数据科学在旧石器考古学中的应用具有三个主要因素,分别是数理统计学、计算机应用,以及旧石器考古学的基础数据与核心科学问题以及理论知识,即采用某种或多种逻辑将旧石器考古学领域的数据进行基于计算机平台的数理统计,并借助计算机语言对庞大的数据进行快速计算,从而帮助我们解释和重建史前人类社会。在目前的旧石器考古学领域,研究者们已经不再满足于对标本所进行的基础的描述性信息统计,对数据进行科学的处理并系统解读的诉求前所未有的强烈,这种诉求不断推动着学科的发展,深化了我们原本对史前社会的认识,甚至开拓出了新的研究领域,极大地推动了旧石器考古学的发展。本文就数据科学的概念、技术路线,以及在旧石器考古学中的应用历史与发展前景做详细介绍,希望通过系统性的梳理,使更多读者熟悉相关的研究手段与具体技术,使更多考古学者对数据科学的应用产生兴趣,从而应用于相关的项目研究中。     

21世纪以来蕨类植物研究论文的发表情况: 基于Web of Science的数据统计

蕨类植物是地球上起源最为古老的维管植物, 在陆生植物演化中具有重要意义。本文通过Web of Science核心数据库(Core Collection)对目前所有关于“fern”、“lycophyte”、“pteridophyte”、“pteridophyta”等的科研论文进行了分析。结果表明: (1) 2000年后, 蕨类植物论文数量增加迅速, 特别是2006年以来增加显著, 现在年均已突破600篇; (2) 2010年以来的以蕨类植物为研究材料和对象的学科和研究领域变得越来越多元化, 多学科结合和交叉的研究方向成为新趋势; (3)中国正在成为蕨类植物研究的热点国家并且成果显著; (4)中国蕨类植物研究在快速发展的同时也出现了各研究机构之间的发展不同步。期望本论文能给蕨类植物的相关研究提供新的方向, 为中国蕨类植物工作者提供借鉴。     

Injuries from antipersonnel mines: the experience of the International Committee of the Red Cross.

OBJECTIVE--To describe and quantify patterns of injury from antipersonnel mines in terms of distribution of injury, drain on surgical resources, and residual disability. DESIGN--Retrospective analysis. SETTING--Two hospitals for patients injured in war. SUBJECTS--757 patients with injuries from antipersonnel mines. MAIN OUTCOME MEASURES--Distribution and number of injuries; number of blood transfusions; number of operations; disability. RESULTS--Pattern 1 injury results from standing on a buried mine. These patients usually sustain traumatic amputation of the foot or leg; they use most surgical time and blood and invariably require surgical amputation of one or both lower limbs. Pattern 2 injury is a more random collection of penetrating injuries caused by multiple fragments from a mine triggered near the victim. The lower limb is injured but there is less chance of traumatic amputation or subsequent surgical amputation. Injuries to the head, neck, chest, or abdomen are common. Pattern 3 injury results from handling a mine: the victim sustains severe upper limb injuries with associated face injuries. Eye injuries are common in all groups. CONCLUSIONS--Patients who survive standing on a buried mine have greatest disability. Non-combatants are at risk from these weapons; in developing countries their social and economic prospects after recovery from amputation are poor.     

Diabetic foot infections: fate of the contralateral foot

Following an initial report urging conservative management of severe diabetic foot infections, the authors have managed 45 patients with a minimum 3-year follow-up. By using standard principles for soft-tissue infection, 78 percent of the patients healed minor amputation sites and maintained biped ambulation following the initial foot involvement. Only 22 percent required a major amputation at the time of the initial foot involvement. The 45 patients were followed and 22 (or 49 percent) developed a severe infection involving the contralateral foot within 18 months. Although 15 of the 22 patients developing contralateral infection (or 33 percent of the total series) required some type of amputation on the contralateral foot, the conservative approach allowed 64 percent of the patients with severe infections in both feet to maintain biped ambulation. This included 40 percent of the patients who required amputation of some portion of both feet.     

Development of the Tardivo Algorithm to Predict Amputation Risk of Diabetic Foot

Diabetes is a chronic disease that affects almost 19% of the elderly population in Brazil and similar percentages around the world. Amputation of lower limbs in diabetic patients who present foot complications is a common occurrence with a significant reduction of life quality, and heavy costs on the health system. Unfortunately, there is no easy protocol to define the conditions that should be considered to proceed to amputation. The main objective of the present study is to create a simple prognostic score to evaluate the diabetic foot, which is called Tardivo Algorithm. Calculation of the score is based on three main factors: Wagner classification, signs of peripheral arterial disease (PAD), which is evaluated by using Peripheral Arterial Disease Classification, and the location of ulcers. The final score is obtained by multiplying the value of the individual factors. Patients with good peripheral vascularization received a value of 1, while clinical signs of ischemia received a value of 2 (PAD 2). Ulcer location was defined as forefoot, midfoot and hind foot. The conservative treatment used in patients with scores below 12 was based on a recently developed Photodynamic Therapy (PDT) protocol. 85.5% of these patients presented a good outcome and avoided amputation. The results showed that scores 12 or higher represented a significantly higher probability of amputation (Odds ratio and logistic regression-IC 95%, 12.2–1886.5). The Tardivo algorithm is a simple prognostic score for the diabetic foot, easily accessible by physicians. It helps to determine the amputation risk and the best treatment, whether it is conservative or surgical management.     

Free flap to the arteria peronea magna for lower limb salvage

A 36-year-old woman sustained an amputation of her right leg at the thigh level and a degloving injury of her left foot and ankle region in an accident during a suicide attempt. Primarily, her left foot was covered with a split skin graft, resulting in a soft-tissue defect at the medial malleolus and at the calcaneus bone. Reconstruction was planned with a free latissimus dorsi muscle flap. Preoperative examinations revealed an arteria peronea magna with a hyperplastic peroneal artery solely providing arterial blood supply to the foot. The arteria peronea magna divided into two branches proximal to the upper ankle joint, replacing the dorsal pedis artery and the medial plantar artery. Tibial posterior and tibial anterior arteries were hypoplastic-aplastic. Microvascular end-to-end anastomoses of the flap vessels to the medial branch ("medial plantar artery") of the arteria peronea magna and its concomitant vein at the medial malleolar bone level were successfully performed. The postoperative course was uneventful. Four weeks postoperatively, the patient started walking assisted by a prosthesis on her right thigh stump. This experience demonstrates that even in a case of arteria peronea magna, free flap surgery for lower limb salvage is a reliable and worthwhile method.     

Effect of denervation on hindlimb regeneration in Xenopus laevis larvae

Xenopus laevis larvae at stages 51-57, according to Nieuwkoop and Faber, were subjected to amputation of the right hindlimb or of both limbs at the thigh or the tarsal level, as well as to somatic denervation of the right limb. Larvae at the same stage having undergone amputation of the right limb or of both limbs and sham denervation of the right limb were used as controls. In experimental series I a single denervation of the right limb was performed at the time of amputation. In experimental series II repeated denervations were performed (before, during and after amputation). Results show that in larvae at stages 51-53 subjected to limb amputation at the proximal level (thigh) even repeated denervation of the right limb did not prevent regeneration, although giving rise to various degrees of hypotrophy. In stage-55 larvae partial inhibition of the regenerative process in the right limb was clearly visible only after repeated denervations and amputation at the proximal level. After amputation at the distal level (tarsalia) the regenerative process in the right limb underwent no significant delay with respect to the controls, although the regenerated right limb was hypotrophic. In stage-57 larvae even a single denervation at the time of amputation was enough to inhibit regeneration of the right limb after either proximal or distal amputation. Therefore, in Xenopus laevis larvae, nerve-dependence for hindlimb regeneration takes place proximodistally as the nerve fibers grow in the limb and it gradually undergoes a process of proximodistal differentiation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Amniogenic band anomalies in a fifth-month fetus and in a newborn from maternal oophorectomy during early pregnancy

A fifth-month fetus and a newborn with amniogenic band anomalies were examined at autopsy. Both specimens were obtained from women who had undergone oophorectomy during early pregnancy. The dead male fetus was aborted spontaneously, and had a micrognathia, a right club foot, and a constriction ring on the left lower leg. The left fingers 2, 3, and 4 were attached to the placenta by a fibrous string. No internal anomaly was noted. In the other case, a male newborn was delivered at the 39th week of gestation and had an agenesis of the calvarium, a cleft lip with palate, an amputation of the right toe, and constriction rings on right fingers 3 and 4 and left finger 3. The placenta was attached to the left temporooccipital region of the head by a fibrous string. Also present was an atrial septum defect and a horseshoe kidney. Possible etiology is discussed in relation to the "amniogenic bands" hypotheses.     

Energy-conserving impact algorithm for the heel-strike phase of gait

Significant ground reaction forces exceeding body weight occur during the heel-strike phase of gait. The standard methods of analytical dynamics used to solve the impact problem do not accommodate well the heel-strike collision due to the persistent contact at the front foot and presence of contact at the back foot. These methods can cause a non-physical energy gain on the order of the total kinetic energy of the system at impact. Additionally, these standard techniques do not quantify the contact force, but the impulse over the impact. We present an energy-conserving impact algorithm based on the penalty method to solve for the ground reaction forces during gait. The rigid body assumptions are relaxed and the bodies are allowed to penetrate one another to a small degree. Associated with the deformation is a potential, from which the contact forces are derived. The empirical coefficient-of-restitution used in the standard approaches is replaced by two parameters to characterize the stiffness and the damping of the materials. We solve two simple heel-strike models to illustrate the shortcomings of a standard approach and the suitability of the proposed method for use with gait.     

A wearable solution for accurate step detection based on the direct measurement of the inter-foot distance

Accurate step detection is crucial for the estimation of gait spatio-temporal parameters. Although several step detection methods based on the use of inertial measurement units (IMUs) have been successfully proposed, they may not perform adequately when the foot is dragged while walking, when walking aids are used, or when walking at low speed. The aim of this study was to test an original step-detection method, the inter-foot distance step counter (IFOD), based on the direct measurement of the distance between feet. Gait data were recorded using a wearable prototype system (SWING^2DS), which integrates an IMU and two time-of-flight distance sensors (DSs). The system was attached to the medial side of the right foot with one DS positioned close to the forefoot (FORE_DS) and the other close to the rearfoot (REAR_DS). Sixteen healthy adults were asked to walk over ground for two minutes along a loop, including both rectilinear and curvilinear portions, during two experimental sessions. The accuracy of the IFOD step counter was assessed using a stereo-photogrammetric system as gold standard. The best performance was obtained for REAR_DS with an accuracy higher than 99.8% for the instrumented foot step and 88.8% for the non-instrumented foot step during both rectilinear and curvilinear walks. Key features of the IFOD step counter are that it is possible to detect both right and left steps by instrumenting one foot only and that it does not rely on foot impact dynamics. The IFOD step counter can be combined with existing IMU-based methods for increasing step-detection accuracy.     

河南淇县宋庄东周墓葬一例殉人骨骼上发现疑似类风湿关节炎

本文介绍了河南淇县宋庄东周贵族墓葬的一例殉人骨骼标本M9-X2,对标本中疑似类风湿关节炎的表现特征进行描述和分析。该殉人的肩、肘、手腕、髋、膝、脚踝等多处关节面的骨质存在对称性侵蚀。相关的X光片显示,侵蚀关节附近有骨质疏松。因未保存全部脊椎和两侧骶髂关节,虽然无法完全排除血清阴性脊椎关节炎的可能,但是对比多种关节疾病的不同骨骼病变特征后认为,该殉人骨质病变更倾向于类风湿关节炎。     

Morphological observations on the congenital malformation of limbs in the Japanese monkey

Congenital malformation of limbs is found in many troops of the Japanese monkey. The author morphologically examined more than ten monkeys with such malformations by means of palpation and Röntgenographing. Anatomical dissection was performed on two of these monkeys. Malformation manifests a considerable variety of forms, from the reduction or absence of fingers to almost total lack of limbs, and is prone to occur in the region of the third finger, the center of malformation, occasionally showing a “split” or “cleft” hand or foot. The latter tendency is more conspicuous in the hand than in the foot. In a word, most of the malformations are characterized by congenital amputation, though the degree varies considerably. The occurrence of supernumerary digits was not found and fusion between fingers was rare. One of the most interesting anatomical results found may be the continuation or fusion between muscles which are normally opposed to each other in action. The occurrence of malformation is more frequent in the male than in the female, and in the hand than in the foot. Little is known about the causes of such malformations, except that they do not occur, at least, according to dominant inheritance.