BMC Psychiatry:催产素受体基因（OXTR）DNA甲基化（DNAM）在人类社会和情感功能中的作用：系统的叙事综述。

神经递质催产素是广泛而闻名its role in the regulation of social bonding as well as romantic attachment. It was initially discovered over 100 years ago after an extract derived from the human posterior pituitary gland was found to cause uterine contractions in pregnant cats. Since 1909 our understanding of this nonapeptide has somewhat progressed.

Impairment of methylation appeared to suggest increased prevalence of mood and anxiety disorders.

催产素结合受体G蛋白耦合的我s coded for by the OXTR gene. Binding of oxytocin to its receptor unleashes a signalling cascade within the cell, leading to both psychological and physiological changes. Much attention has been given to the OXTR gene as its expression essentially controls the rate limiting step in the oxytocin signalling process.

发表在BMC Psychiatrythis month looks at the possibility of a link between OXTR gene methylation and corresponding changes in social and emotional behaviour in human populations.

尽管仍然没有足够的证据来得出强烈的结论，但早期发现表明甲基化模式与认知和社会情感行为受损之间存在相关性。相反，甲基化的损害似乎表明情绪和焦虑症的患病率增加。

To establish these patterns with greater certainty, more research is required to understand the relationship between OXTR gene methylation and OXTR expression.

BMC Public Health:Sound pressure levels generated at risk volume steps of portable listening devices: types of smartphone and genres of music.

It is thought that approximately 36% of the world’s population currently use a smart phone, with around 2.1 billion worldwide users reported in 2016. A significant number of these smartphone owning individuals are likely to take advantage of music playing applications found ubiquitously across most smartphone models.

However, listening to music on a smartphone or personal listening device comes with a risk.

世界卫生组织（WHO）警告说，许多年轻人有频繁暴露于嘈杂的环境而导致娱乐噪声引起的听力损失的风险。人们认为，发达县的12至35岁年龄较大的年轻人中，有近50％的年轻人通过他们的个人听力设备暴露于危险的高水平音乐。

Smartphone manufacturers have now implemented their own recommendations for minimum volumes at which hearing loss may occur. However these volumes vary, even within different smartphone models issued by the same company.

InBMC Public Health，作者Gibbeum Kim和Woojae Han使用四种类型的韩国流行音乐来确定每个设备定义的第一个风险量水平。

结果表明，在六个设备中检测到的声压水平有很大的8 dB差异，舞蹈流行音乐的流派测试水平最高。基于这些结论，建议在所有设备中实施用于安全使用的国际标准。

BMC国际健康与人权:Causes of death among street-connected children and youth in Eldoret, Kenya.

众所周知，无家可归者的预期寿命平均要比其住所和定居者较低。最近的一项研究估计，旧金山无家可归的年轻人的死亡率是普通人群的10倍。与药物有关的死亡和自杀是最常见的原因。

但是，关于低收入和中等收入国家的青年死亡率原因的信息很少。最近发表的一项研究在BMC国际健康与人权中已经记录了肯尼亚埃尔多雷特的街头连接青年的死亡原因。

The causes of death of in Eldoret differ considerably from those in San Francisco. In Eldoret, HIV accounted for 37% of all deaths, killing 59% of females included in the study and roughly a quarter of all men. Among the male population, the greatest cause of death was assault, accounting for nearly 50% of recorded deaths in men.

Deaths for reasons such as these are largely preventable. The authors advocate appropriate responses such as targeted HIV treatment programs and child protection systems to decrease the prevalence of assault and HIV and thus avoidable youth mortality in these areas.

BMC进化生物学：Phylogenomic analysis of Apoidea sheds new light on the sister group of bees

这项发表在BMC Evolutionary Biologyinvestigates the evolutionary history of apoidea, a superfamily that includes apoid wasps and bees. A barrier to understanding the evolution of apoidea has been the difficulty in determining the geological age of bees as well as their phylogenetic origin.

柏林进化与生物多样性科学研究所的迈克尔·奥尔（Michael Ohl）的小组汇总和分析了目标DNA富集位点和转录组序列数据，涵盖了Apoidea超级家族中的所有主要谱系。

The Ammoplanina, a family of predatory wasps, began to lose their taste for thrips around 128 million years ago. Over time, they acquired a plant-based diet and evolved into what we now know as the modern bee. Further research must be done to understand the specific traits that enabled this radical dietary change.

BMC医学伦理：Conscientious objection to participation in abortion by midwives and nurses: a systematic review of reasons

在《欧洲人权公约》中所包含的是思想良心和宗教自由的权利。但是，如果认为要对公共卫生构成风险，或侵犯他人的权利和自由，则可以限制表现出这些信念的自由。

Conscientious objection was widely accepted, despite largely polarised viewpoints on either side of the debate.

Under most abortion laws enacted across the developed world, a conscience clause is included, permitting the conscientious objection of healthcare professionals to opt out of providing such services on moral grounds.

Heated debate has ensued regarding the extent to which the rights of healthcare professionals to refuse provision of abortion services should be limited, in case this should infringe on a woman’s legal right to the service.

This review, published inBMC医学伦理，旨在阐明拒绝以良心为由进行流产的原因。令人惊讶的是，尽管是世卫组织推荐的堕胎服务提供者，但发现助产士和护士的观点在很大程度上没有。在所研究的文献中，尽管在辩论的两边都有极度两极分化的观点，但认真的反对被广泛接受。

Going forward, better representation of all relevant healthcare professionals in the debate and the consideration of all viewpoints is necessary when discussing such a sensitive topic, in order to inform beneficial health policy in this area.

BMC Oral Health:Cone beam computed tomography in implant dentistry: recommendations for clinical use

Between the ages of 35 to 44, 69% of US citizens are reported to have lost at least one tooth. 15 million of this population will have undergone crown and bridge replacements for missing teeth, while only 3 million of these have been reported to have had dental implants. However this number is said to be growing by half a million every year.

Dental implants may be surgically inserted into a patient’s jaw, in order to support the introduction of a prosthetic element such as a crown or bridge. Cone beam computed tomography (CBCT) is a useful tool, providng high-quality, 3-dimensional images of surrounding tissues to aid this process. The low cost and reasonable dose of radiation administered has caused the popularity of this method to increase over recent years.

InBMC Oral Health本月，迈克尔·伯恩斯坦（Michael Bornstein）来自比利时鲁文大学（University of Belgium）评论当前文献的小组，为将来使用CBCT成像提供了建议。由于辐射剂量相对较高，因此应证明其临床用法是合理的。例如，作者建议将CBCT限制在牙科植入物插入后涉及术后并发症的病例中，以及在长期维持和牙科植入物的后续过程中避免此程序。

不同CBCT机器之间缺乏辐射剂量和图像质量的标准化进一步促使呼吁进行更多的研究，以持续达到最低的诊断可接受的辐射剂量。