Emerging innovations in cold plasma therapy against cancer: A paradigm shift

Cancer is one of the major causes of mortality, accounting for ～ 9.5 million deaths globally in 2018. The spectrum of conventional treatment for cancer includes surgery, chemotherapy and radiotherapy. Recently, cold plasma therapy surfaced as a novel technique in the treatment of cancer. The FDA approval of the first trial for the use of cold atmospheric plasma (CAP) in cancer therapy in 2019 is evidence of this. This review highlights the mechanisms of action of CAP. Additionally, its applications in anticancer therapy have been reviewed. In summary, this article will introduce the readers to the exciting field of plasma oncology and help them understand the current status and prospects of plasma oncology.     

Effect of increasing CO2 on the terrestrial carbon cycle

Feedbacks from the terrestrial carbon cycle significantly affect future climate change. The CO₂ concentration dependence of global terrestrial carbon storage is one of the largest and most uncertain feedbacks. Theory predicts the CO₂ effect should have a tropical maximum, but a large terrestrial sink has been contradicted by analyses of atmospheric CO₂ that do not show large tropical uptake. Our results, however, show significant tropical uptake and, combining tropical and extratropical fluxes, suggest that up to 60% of the present-day terrestrial sink is caused by increasing atmospheric CO₂. This conclusion is consistent with a validated subset of atmospheric analyses, but uncertainty remains. Improved model diagnostics and new space-based observations can reduce the uncertainty of tropical and temperate zone carbon flux estimates. This analysis supports a significant feedback to future atmospheric CO₂ concentrations from carbon uptake in terrestrial ecosystems caused by rising atmospheric CO₂ concentrations. This feedback will have substantial tropical contributions, but the magnitude of future carbon uptake by tropical forests also depends on how they respond to climate change and requires their protection from deforestation.In projections of future climate, the carbon cycle is second only to physical climate sensitivity itself in contributing uncertainty (1). Earth system model uncertainty has increased as more mechanisms have been incorporated into a growing number of increasingly sophisticated models. Terrestrial ecosystem feedbacks to atmospheric CO₂ concentration result from two mechanisms, direct effects of CO₂ on photosynthesis and effects of climate change on photosynthesis, respiration, and disturbance (2). The CO₂ effect, used here to describe the effect of increasing atmospheric CO₂ on terrestrial carbon storage by increasing photosynthetic rates, is also known as the β effect (3, 4). The effects of CO₂ on carbon uptake occur at the enyzmatic and stomatal scales but impact the global carbon cycle.The CO₂ effect on terrestrial carbon storage is a key potential negative feedback to future climate, and in models of the present, it is the largest carbon cycle feedback (5, 6). In simulations of the next century, the CO₂ effect is four times larger than the climate effect on terrestrial carbon storage and twice as uncertain (4). Land use also creates large fluxes, but these are not driven by CO₂ or climate directly and so are not feedbacks. In models of the future, the biosphere operates as a net sink, reducing the climate impact of fossil fuel and deforestation emissions, until positive feedbacks from climate change [reduced productivity, increased respiration, or dieback (7)] and land use emissions exceed the CO₂ effect. The magnitude of this negative feedback is crucial to simulating future climate, but because observational constraints on the CO₂ effect are limited, the effects of CO₂ remain controversial. The effects of CO₂ are known mainly from small-scale experimental studies, ranging from single-leaf experiments through to ecosystem-scale experiments with a spatial scale of hundreds of meters (8), but predictions from theory of a large tropical effect of CO₂ have appeared to be inconsistent with global patterns of atmospheric CO₂ (6).Photosynthesis increases with increasing CO₂ following a Michaelis−Menton curve, and this effect grows stronger at higher temperatures, implying, all else being equal, larger effects in warmer climates (9–11), especially in the tropics. Many factors control the relationship between increased photosynthetic rate and carbon storage, including how fixed carbon is allocated to plant tissues and soils with different residence times, the development of progressive nitrogen limitation, interactions with water or light limitation, and many other biological responses (12). Theory and experiments agree in suggesting a CO₂-driven net sink that should be roughly proportional to overall productivity (13) leading to a large sink in the tropics, a prediction that should be testable with global observations (11).     

Producing desired ice faces

The ability to prepare single-crystal faces has become central to developing and testing models for chemistry at interfaces, spectacularly demonstrated by heterogeneous catalysis and nanoscience. This ability has been hampered for hexagonal ice, I_h––a fundamental hydrogen-bonded surface––due to two characteristics of ice: ice does not readily cleave along a crystal lattice plane and properties of ice grown on a substrate can differ significantly from those of neat ice. This work describes laboratory-based methods both to determine the I_h crystal lattice orientation relative to a surface and to use that orientation to prepare any desired face. The work builds on previous results attaining nearly 100% yield of high-quality, single-crystal boules. With these methods, researchers can prepare authentic, single-crystal ice surfaces for numerous studies including uptake measurements, surface reactivity, and catalytic activity of this ubiquitous, fundamental solid.Studies of model, single-crystal surfaces have revolutionized understanding of a vast array of heterogeneous catalysts and nanoparticles ranging from pure metals to alloys to semiconductors. Applying the single-crystal surface strategy to ice––arguably one of the most fundamental and ubiquitous hydrogen-bonded interfaces––has been limited due to challenges associated with surface generation. As a result, questions about molecular-level dynamics, surface binding site patterns, and the molecular-level structure remain unanswered (1). Several strategies have been adopted for studying ice: (i) Depositing solid water on a metal or ionic substrate that matches the oxygen lattice (2, 3). However, ice on a substrate often has distinctly different properties from those of neat ice; indeed, such ice can even be hydrophobic (4, 5)! (ii) Uptake measurements often use a Knudsen cell with vapor-deposited ice on a substrate (6) or compacted, finely divided, artificial snow (7) to arrive at a molecular-level picture for gas–particle interaction despite the irregular, highly variable surfaces used. (iii) Small crystallites can be well characterized but, as highlighted by Libbrecht and Rickerby (8), results can be clouded by competition from nearby crystallites; small faces compete with adjacent faces. In addition, crystallites are perturbed by the supporting surface. It is therefore desirable to prepare macroscopic samples with known faces.Interactions at ice surfaces have a particularly profound effect on climate. For example, correlational studies suggest that rain formation depends on ice particles in clouds (9), but not all ice-containing clouds yield rain. It is thought that variation in supersaturation and the mechanism for gathering water molecules by ice particles profoundly affects precipitation. Discrepancies between experiment and theory are often rationalized as a result of irregular shapes, inelastic scattering, or differing binding sites leaving large uncertainties for climate models (10). More reproducible, well-characterized surfaces of I_h––the most stable form of ice at ambient pressure––are needed to bring clarity.Ice is unusual in that the macroscopic sample does not reveal the crystal lattice orientation. Neighboring grain lattice orientation is a critical issue in the ice-core and glaciology communities (11). Hence, previous work (12–14) focused on determining grain orientation with respect to the grain boundary. The most quantitative of these are the two methods of Matsuda (12). The first uses etch pits measuring lengths inside the pit. Large uncertainties in length measurements result in large uncertainties in lattice axis orientation angles; this is not a major issue for grain growth studies but is a serious problem for generating targeted faces. The second method measures only the azimuths, thus incompletely determining orientation. Both methods break down if the optic axis is near-parallel to the surface, and neither provides the tools required to accurately orient a macroscopic sample to generate a targeted face. Lattice orientation could be determined with X-ray methods (15, 16) provided such determination includes a connection to the macroscopic sample. For wide-spread use, a laboratory-based method is preferable. This work describes two methods to fill this important need. The first uses pit perimeter ratio measurements; because the perimeter is sharp, accuracy is greatly improved. The second method locates the optic axis via cross-polarizers (11, 17), then precisely determines the hexagonal orientation via etching. Closed-form, analytical formulas are derived relating lattice orientation to the macroscopic sample. These orientation formulas feed into rotation matrices generating additional analytical formulas enabling precise cutting of any targeted face. The result is illustrated by cutting each of the three major ice faces. These techniques provide researchers with the tools needed to prepare neat ice surfaces.This work specifically describes face preparation from cylindrical boules (18); however, the method is easily adapted to any macroscopic, single-crystal geometry. Due to nearly equal energy faces, ice takes on the shape of the confining container. The near-energy match is demonstrated by growth in the modified Bridgeman apparatus (19). Nucleation occurs on a polycrystalline seed; single-crystal growth is achieved due to competitive growth among the multiple ice–water interfaces (18). Careful thermal management maintains near-equilibrium conditions yielding a large single crystal, but the crystal orientation is not a priori known. [Note: ice seeded by a floating crystal tends to have the optic axis perpendicular to the growth direction but single-crystal yield is low, ~10% (20).] Close energy match among the faces also means that ice does not readily cleave along any lattice plane (21). Thus, successful face preparation for any ice sample begins with characterization of the lattice orientation.     

不同粒径大气颗粒物与死亡终点关系的流行病学研究回顾

越来越多的国内外流行病学调查与研究发现,大气颗粒物的暴露与居民不同疾病死亡率的上升存在着显著的相关关系。本文就不同粒径颗粒物与最严重的健康终点——死亡之间关系的流行病学研究,进行较为系统的回顾和评述。指出:大多数研究就可吸入颗粒物(PM10)对死亡终点的影响已进行了较为系统和深入的探讨,目前研究重点向细颗粒物(PM2.5)对健康终点的影响转移。而粗颗粒物(PM10~2.5)以及与PM2.5之间的比较性研究资料还较为有限。超细颗粒物(PM0.1)的暴露及健康影响数据也很有限。但由于其数量浓度的优势,可能会成为未来流行病学研究的重点。     

气候因素对青铜文物模拟材料大气腐蚀的影响

运用QCM反应性监测方法研究了暴露在博物馆模拟展柜中的青铜文物模拟材料的腐蚀行为及规律,并利用扫描电镜(SEM)、能谱仪(EDS)以及光电子能谱(XPS)分析手段,对青铜文物模拟材料在腐蚀60 d后的腐蚀形貌与产物进行了分析。结果表明:光照的存在以及温度、湿度的升高都会加速青铜文物模拟材料的腐蚀,其中ERCO LED灯在色温为4 000 K时对青铜文物模拟材料的腐蚀影响最严重,在腐蚀60 d后的主要腐蚀产物为Cu₂O、CuO、SnO、SnO₂,还有少量铜的碳酸盐、铜的硫酸盐与铜的硫化物、铜的硝酸盐与亚硝酸盐、铜的氯化物。     

咽后壁瓣修复术后并发阻塞性睡眠呼吸暂停的临床研究

探讨腭裂术后腭咽闭合不全（VPI）患者行咽后壁瓣修复术（PFS）后阻塞性睡眠呼吸暂停（OSA）的发生率及严重程度，并探讨手术年龄对OSA发生率及严重程度的影响。     

Photochemistry of aqueous pyruvic acid

The study of organic chemistry in atmospheric aerosols and cloud formation is of interest in predictions of air quality and climate change. It is now known that aqueous phase chemistry is important in the formation of secondary organic aerosols. Here, the photoreactivity of pyruvic acid (PA; CH₃COCOOH) is investigated in aqueous environments characteristic of atmospheric aerosols. PA is currently used as a proxy for α-dicarbonyls in atmospheric models and is abundant in both the gas phase and the aqueous phase (atmospheric aerosols, fog, and clouds) in the atmosphere. The photoreactivity of PA in these phases, however, is very different, thus prompting the need for a mechanistic understanding of its reactivity in different environments. Although the decarboxylation of aqueous phase PA through UV excitation has been studied for many years, its mechanism and products remain controversial. In this work, photolysis of aqueous PA is shown to produce acetoin (CH₃CHOHCOCH₃), lactic acid (CH₃CHOHCOOH), acetic acid (CH₃COOH), and oligomers, illustrating the progression from a three-carbon molecule to four-carbon and even six-carbon molecules through direct photolysis. These products are detected using vibrational and electronic spectroscopy, NMR, and MS, and a reaction mechanism is presented accounting for all products detected. The relevance of sunlight-initiated PA chemistry in aqueous environments is then discussed in the context of processes occurring on atmospheric aerosols.     

From the Cover: Quasiresonant amplification of planetary waves and recent Northern Hemisphere weather extremes

In recent years, the Northern Hemisphere has suffered several devastating regional summer weather extremes, such as the European heat wave in 2003, the Russian heat wave and the Indus river flood in Pakistan in 2010, and the heat wave in the United States in 2011. Here, we propose a common mechanism for the generation of persistent longitudinal planetary-scale high-amplitude patterns of the atmospheric circulation in the Northern Hemisphere midlatitudes. Those patterns—with zonal wave numbers m = 6, 7, or 8—are characteristic of the above extremes. We show that these patterns might result from trapping within midlatitude waveguides of free synoptic waves with zonal wave numbers k ≈ m. Usually, the quasistationary dynamical response with the above wave numbers m to climatological mean thermal and orographic forcing is weak. Such midlatitude waveguides, however, may favor a strong magnification of that response through quasiresonance.     

Nitrosamine Contamination in Pharmaceuticals: Threat,Impact, and Control

Nitrosamine-contaminated medicinal products have raised safety concerns towards the use of various drugs, not only valsartan and all tetrazole-containing angiotensin II receptor blockers, but also ranitidine, metformin, and other medicines, many of which have been recalled and prone to shortage. At any stages, from drug substance synthesis throughout each product's lifetime, these impurities may evolve if an amine reacts with a nitrosating agent coexisting under appropriate conditions. Consequently, drug regulatory authorities worldwide have established stringent guidelines on nitrosamine contamination for all drug products in the market. This review encompasses various critical elements contributing to successful control measures against current and upcoming nitrosamine issues, ranging from accumulated knowledge of their toxicity concerns and potential root causes, precise risk evaluation, as well as suitable analytical techniques with sufficient sensitivity for impurity determination. With all these tools equipped, the impact of nitrosamine contamination in pharmaceuticals should be mitigated. An evaluation aid to tackle challenges in risk identification, as well as suitable industry-friendly analytical techniques to determine nitrosamines and other mutagenic impurities, are among unmet needs that will significantly simplify the risk assessment process.