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Extracellular vesicles (EVs) are receiving increasing attention in recent years in the field of cancer treatment. EVs contain specific contents closely related to their donor cells, such as miRNAs, proteins and dsDNAs. As endogenous vesicles, EVs naturally have the characteristics of low toxicity and low immunogenicity and can stably pass through the circulatory system to reach the recipient cells, which make them good carriers to deliver therapeutic agents such as nucleic acid sequences and chemotherapeutics. In many preclinical studies and clinical trials, EVs have demonstrated their unlimited advantages in the field of cancer therapy. However, there are still some challenges that restrict their clinical application, such as yield, heterogeneity, safety, and specificity. In this review, we will focus on the latest breakthrough of EVs in the field of cancer treatment and discuss the challenges in the clinical translation of EVs.

The condensate flooding during dropwise condensation causes serious deterioration in heat transfer performance. In this study, the three-dimensional large-scale molecular dynamics simulation is carried out to investigate the droplet state transition from local flooding mode to Wenzel or from Wenzel to Cassie due to the droplet coalescence under the effect of nanostructure size. In particular, the effect of nanostructure breakage on droplet nucleation and growth is discussed to reveal the mechanism of dropwise condensation heat transfer deterioration. As a potential solution, the lubricant-impregnated surface is proposed to recover the preferred Cassie state by regulating the dynamic wetting characteristics of droplets, and thus the detrimental effect of nanostructure breakage could be effectively avoided.

Radiation pressure refers to the momentum transfer of photons during light "particles" impacting a surface. The force is too small to drive microengines. Different from the classical radiation pressure, the indirect radiation pressure (F m ) is introduced, coming from the momentum change of light-induced bubble expansion. F m is shown to obey F m ∼ (I·r b ) 2 , behaving faster growth of indirect radiation pressure versus light intensity I and bubble radius r b . An effective bubble size range is identified for F m to suppress other forces for bubble in liquid. The top laser irradiation on nanofluid is used in this experiment. A well-defined bubble pulsating flow, being a new principle of bubble piston engine, is demonstrated. During pulse on (≈ns scale), F m exceeding other forces generates an extremely large acceleration, which is three to four orders larger than the gravity acceleration, propelling the bubble traveling downward. During pulse off, the bubble is floating upward due to the nonexistence of F m . In such a way, the piston engine sustains the oscillating ranges of 38-347 µm for bubble diameters and 2.7-457.9 µm for traveling distances of piston. This work is useful to manipulate bubble dynamics in solar energy systems, and can find various applications in optofluidics., (© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Carbon emissions are the primary reason that contributes to global warming. The gradient has a significant impact on the carbon dioxide (CO2) emissions produced by trucks. The aim of the current paper is to propose a carbon emission quantification model for diesel trucks on longitudinal slope sections and investigate the influence of gradient on the carbon emissions of trucks for use in the low-carbon highway design. The law of conservation of mechanical energy, the first law of thermodynamics, and the vehicle longitudinal dynamics theory were adopted for deriving the carbon emission model of the trucks on the flat, uphill, downhill and round-trip longitudinal slope segments. Three kinds of common trucks were chosen to conduct the field test. Following the test data, the model demonstrates a high accuracy. The minimum gradient which is expected to impact carbon emissions of trucks on the round-trip longitudinal slope sections was the balance gradient as revealed. The gradient of the longitudinal slope is required to be avoided to be greater in comparison with the balance gradient for the achievement of the two-way traffic low carbon operation on a highway. The results of this study are valuable to researchers interested in low carbon road design and low carbon transportation control., Competing Interests: The authors have declared that no competing interests exist.

It is great significance to understand the mechanism of heat transfer deterioration of supercritical CO 2 for heat exchanger design and safe operation in the supercritical CO 2 Brayton cycle. Three-dimensional steady-state numerical simulation was performed to investigate the behavior of supercritical CO 2 heat transfer in heated vertical up-flow tube with inner diameter d i = 10 mm and heated length L h = 2000 mm. Based on the characteristics of inverted-annular film boiling at subcritical pressure, the heat transfer model of supercritical CO 2 flowing in the heated vertical tube was established in this paper. The mechanisms of heat transfer deterioration (HTD) and heat transfer recovery (HTR) for supercritical CO 2 were discussed. Numerical results demonstrate that HTD is affected by multiple factors, such as the thickness and property of vapor-like film near the wall, the turbulence intensity near the interface between liquid-like and vapor-like, and in the liquid-like core region as well as the distribution of radial velocity vector. Among the above factors, the change of turbulent kinetic energy caused by the buoyancy effect seems to be a more important contributor to HTD and HTR. Furthermore, the influences of heat flux and mass flux on the distribution of wall temperature were analyzed, respectively. The reasons for the difference in wall temperature at different heat fluxes and mass fluxes were explained by capturing detailed thermal physical properties and turbulence fields. The present investigation can provide valuable information for the design optimization and safe operation of a supercritical CO 2 heat exchanger.

Heavy-duty trucks contribute a significant component of all transportation in cargo terminals, such as Shaanxi Province, China. The emissions from these vehicles are the primary source of carbon emissions during highway operations. While several studies have attempted to address emission issues by improving traffic operations, a few focused on the relationship between emissions and highway geometric design, especially for heavy-duty trucks. The primary goal of this research was to understand the impact of circular curve on carbon dioxide (CO 2 ) emissions produced by heavy-duty diesel trucks. Firstly, appropriate parameters were specified in MOVES (motor vehicle emission simulator) model according to the geometrical characteristics. Fuel consumption, speed and location data were collected by hiring five skilled drivers on the automotive proving ground located at Chang'an University, Shaanxi Province. The associated carbon emission data were derived from fuel consumption data by applying the IPCC (Intergovernmental Panel on Climate Change) method. After this, the applicability of MOVES model was verified by the field experiment. Moreover, a multiple regression model for CO 2 emissions incorporated with roadway segment radius, circular curve length, and initial vehicle speed was established with data generated by the MOVES model. The proposed CO 2 emission model was also verified by field experiment with relative error of 6.17%. It was found that CO 2 emission had monotone decreasing property with radius increasing, and the minimum radius that influenced diesel CO 2 emission was 550 m. The proposed quantitative CO 2 emission model can provide a reference for low-carbon highway design, leading to environment-friendly transportation construction.

It is difficult to recover the residual heat from flue gas when supercritical carbon dioxide (S-CO 2 ) cycle is used for a coal fired power plant, due to the higher CO 2 temperature in tail flue and the limited air temperature in air preheater. The combined cycle is helpful for residual heat recovery. Thus, it is important to build an efficient bottom cycle. In this paper, we proposed a novel exergy destruction control strategy during residual heat recovery to equal and minimize the exergy destruction for different bottom cycles. Five bottom cycles are analyzed to identify their differences in thermal efficiencies ( η th,b ), and the CO 2 temperature entering the bottom cycle heater ( T 4 b ) etc. We show that the exergy destruction can be minimized by a suitable pinch temperature between flue gas and CO 2 in the heater via adjusting T 4 b . Among the five bottom cycles, either the recompression cycle (RC) or the partial cooling cycle (PACC) exhibits good performance. The power generation efficiency is 47.04% when the vapor parameters of CO 2 are 620/30 MPa, with the double-reheating-recompression cycle as the top cycle, and RC as the bottom cycle. Such efficiency is higher than that of the supercritical water cycle power plant.

The polymerase chain reaction (PCR) technique has been widely used in fields of molecular biology and diagnosis. PCR biochip/microdevice is increasingly of great interest as a result of its small volume of sample and reaction mixture, short reaction period and portability. The applications of PCR biochip/microdevice are specially introduced in the clinical diagnosis. Finally, the applications and development of PCR biochip/microdevice are also predicted.

Background: To investigate pathologically the characteristics of proximal bronchial invasion of lung cancer, and to provide the theoretic basis for the selection of a proper operation mode., Methods: A total of 398 patients with lung carcinoma underwent radical pulmonectomy and systematic lymphadenectomy. The proximal bronchi and the hilar and mediastinal lymph nodes of their operatively resected specimens were selected for pathological study., Results: (1)The direct invasion of cancerous cells through mucous, submucous or multiple layers was the most frequent way during lung cancer spread, rating 9.3%, 21.8% and 68.9% respectively. 96.4% of the cancerous invasion occurred at the proximal bronchial wall less than 1.5 cm apart from the cancer margin. The extension of invasion correlated with the histopathologic type of cancer, mode of invasion and TNM classification. (2)The cancer infiltration by the nodes metastasizing into the bronchus wall (bronchial external tunica or cartilage) was also an important way for the cancer to spread, especially in adenocarcinoma. The poor differentiated adenocarcinoma has significantly higher metastatic rate and infiltration rate than the well differentiated ( P < 0.01, P < 0.01). There were 22 such cases, including 3 of lobar bronchus wall invaded by N1 metastasis and 19 of main bronchus wall by N2 metastasis., Conclusions: For radical removal of tumor, the key point for selecting a rational operation mode is to keep a distance of 1.5 cm or more between the excision margin of the bronchus and the tumor, to pay attention to the bronchial wall invasion caused by the metastatic lymph nodes, even in peripheral adenocarcinoma, and to dissect extensively and completely the lymph nodes of the hilar and upper and lower mediastinum at the homolateral thoracic cavity.