A highly degradable Mg-Al-Ca alloy with superior anti-tumor efficacy

Molecule hydrogen(H_(2)) has been used to suppress tumor growth. To employ the H_(2) therapy, it is necessary to use a proper agent for continuous generation of H_(2). As a biodegradable metal, magnesium(Mg) generates H_(2) in an aqueous environment, but the H_(2) release rate is still too low. Here, we design a Mg-Al-Ca(AX) alloy that degrades very rapidly due to the presence of a secondary phase Al_(2)Ca. Having a reduction potential much higher than Mg and any other Mg-based secondary phases, Al_(2)Ca accelerates the corrosion of the Mg matrix by a micro-galvanic process. Al_(2)Ca also enhances the strength and ductility of the AX alloy. AX alloy rods show better anti-tumor efficacy than pure Mg rods in vivo. Moreover, implanted AX alloy rods can be heated under an alternating magnetic field to suppress large-size tumors.This work suggests that the H_(2) therapy using highly degradable Mg alloys may provide an effective cancer treatment.

热消融治疗肺部亚实性结节专家共识(2021年版)

局部热消融技术在肺部结节治疗领域正处在起步与发展阶段,为了肺结节热消融治疗的临床实践和规范发展,由"中国医师协会肿瘤消融治疗技术专家组""中国医师协会介入医师分会肿瘤消融专业委员会""中国抗癌协会肿瘤消融治疗专业委员会""中国临床肿瘤学会消融专家委员会"组织多学科国内有关专家,讨论制定了"热消融治疗肺部亚实性结节专家共识(2021年版)"。主要内容包括:(1)肺部亚实性结节的临床评估;(2)热消融治疗肺部亚实性结节技术操作规程、适应证、禁忌证、疗效评价和相关并发症;(3)存在的问题和未来发展方向。

shRNA-mediated Slc38a1 silencing inhibits migration, but not invasiveness of human pancreatic cancer cells

Objective：Early metastasis is a major biological feature of pancreatic cancer.The current study examined whether silencing Slc38a1,a gene involved in energy metabolism,using short hairpin RNA （shRNA） could inhibit the growth,migration,and invasiveness of pancreatic cancer cells.Methods：A series of Slc38a1 shRNAs were designed and cloned into the pGPU6/GFP/Neo vectors.An shRNA with the most efficacious inhibitory action on SCL38A1 expression （65％ inhibition） upon screening in DH5α bacteria was used to transfect SW1990 human pancreatic cancer cells.Cell growth,migration,and invasiveness were examined using cell counting kit-8,Boyden chamber without and with Matrigel,respectively.Results：Transfection of SW1990 cells with the SLCs38A1 shRNA significantly decreased the proliferation （P＜0.0001） and migratory potential （by 46.7％,P=0.0399） of the cancer cells.Invasiveness,however,was not affected.Conclusions：Inhibiting Slc38a1 using shRNA technology could decrease the growth and migration of representative pancreatic cancer cells.However,the fact that invasiveness was not affected suggested that SLC38A1 is unlikely to be responsible for early metastasis.

Phase Ⅲ Clinical Trials of the Cell Differentiation Agent-2 （CDA-2）： Therapeutic Efficacy on Breast Cancer, Non-Small Cell Lung Cancer and Primary Hepatoma

OBJECTIVE The objective of this study was to explore the effect of CDA-2, a selective inhibitor of abnormal methylation enzymes in cancer cells, on the therapeutic efficacy of cytotoxic chemotherapy. METHODS Advanced cancer patients, all of whom had previously undergone chemotherapy, were randomly divided into 2 groups, one receiving chemotherapy only as the control group, and the other receiving CDA-2 in addition to chemotherapy as the combination group. The therapeutic efficacies and the toxic maniestations of the 2 groups were compared based on the WHO criteria. RESULTS Of 454 cancer patients enrolled in phase Ⅲ clinical trials of CDA-2, 80, 188, and 186 were breast cancer, NSCLC, and primary hepatoma patients, respectively. Among them 378 patients completed treatments according to the protocols. The results showed that the overall effective rate of the combination group was 2.6 fold that of the control group, 4.8 fold in the case of breast cancer, 2.3 fold in the case of primary hepatoma, and 2.2 fold in the case of NSCLC. Surprisingly, the combination therapy appeared to work better for stage Ⅳ than stage Ⅲ patients. CDA-2 did not contribute additional toxicity. On the contrary, it reduced toxic manifestations of chemotherapy, particularly regarding white blood cells, nausea and vomiting. CONCLUSION Modulation of abnormal methylation enzymes by CDA-2 is definitely helpful to supplement chemotherapy. It significantly increased the therapeutic efficacy and reduced the toxic manifestation of cytotoxic chemotherapy on breast cancer and NSCLC.

3D Physical Simulation of Water Flooding Characteristics of Buried Hill Reservoir with Different Fracture Systems

In order to understand the water-flooding characteristics of different fracture systems in metamorphic rock buried hill reservoirs and the mechanism of improving water-flooding development effect, a three-dimensional physical model of fractured reservoirs is established according to the similarity criterion based on the prototype of metamorphic buried hill reservoirs in JZ Oilfield in Bohai Bay Basin. Combined with the fractured reservoir characteristics of JZ Oilfield, the water displacement characteristics of the top-bottom staggered injection-production well pattern in different fracture network mode and different fracture development degree of buried hill reservoir are studied. The experimental results show that: 1) the more serious the fracture system irregularity is, the shorter the water-free oil production period is and the lower the water-free oil recovery is. After water breakthrough of production wells, the water cut rises faster, and the effect of water flooding development is worse;2) under the condition of non-uniform fracture development, the development effect of the bottom fracture undeveloped is better than that of the middle fracture undeveloped. Water injection wells are deployed in areas with relatively few fractures, while oil wells are deployed in fractured areas with higher oil recovery and better development effect.

Sliding-Mode Control Based on Index control Law for MPPT in Photovoltaic Systems

A novel maximum power point tracking method based on sliding mode control and average state model of PV generation systems is developed.This method consists of two parts:term of constant control and term of index control.It is different from the conventional sliding mode control which uses a constant speed control law.The developed method uses a controllable sliding mode switching function which can automatically adjust the approaching speed,so as to enable the photovoltaic system to achieve fast dynamic response and stable output power.System simulations using MATLAB are performed.Compared with conventional methods,simulation results show that maximum power point tracking times for the novel method both in start-up phase and in cases of environmental changes can be shorten by more than 50%.A experimental platform of 150W PV system has been established to conduct tests.Experimental results show that the maximum power point tracking times both in start-up phase and in load stepping phase including the illumination change phase,can be significantly decreased.These results indicate that the developed method owns better dynamic response than constant speed control law.It can be used in photovoltaic generation system.

Remaining Oil Distribution Law and Potential Tapping Strategy of Horizontal Well Pattern in Narrow Oil Rim Reservoir with Gas Cap and Edge Water

For thin oil rim reservoir with gas cap and edge water, it is helpful to improve the development effect to find out the distribution law of remaining oil in this kind of reservoirs. For this reason, taking the narrow oil rim reservoir with gas cap and edge water of Oilfield A in Bohai Sea as a case, the main controlling factors, including reservoir structure, fault, gas cap energy, edge water energy and well pattern, affecting the distribution of residual oil in this kind of reservoir were analyzed by using the data of core, logging, paleogeomorphology and production. Then, the distribution law of remaining oil was summarized. Generally, the remaining oil distribution is mainly potato-shaped or strip-shaped in plane. Vertically, it depends on the energy of gas cap and edge water. For the reservoir with big gas gap and weak edge water, the remaining oil mainly lies in the bottom of oil column. And for the reservoir with small gas gap and strong edge water, the remaining oil mainly locates at the top of oil column. Aiming at different distribution modes of remaining oil, the corresponding potential tapping strategies of horizontal wells are put forward: in the late stage of development, for the reservoir with big gas gap and weak edge water, the remaining oil concentrates at the bottom of the oil column, and the position of horizontal well should be placed at the lower 1/3 to the lower 1/5 of the oil column;for the reservoir with small gas cap and strong edge water, the remaining oil locates at the top of the oil column, and the position of horizontal well should be put at the upper 1/5 to the upper 1/3 of the oil column height, vertically. Based on the study on remaining oil of Oilfield A, a potential tapping strategy of well pattern thickening and vertical position optimization of horizontal well was proposed. This strategy guided the efficient implementation of the comprehensive adjustment plan of the oilfield. Moreover, 18 infill development wells were implemented in Oilfield A, and the average production of the infill wells is 2.1 times that of the surrounding old wells. It is estimated that the ultimate recovery factor of the oilfield will reach 33.9%, which is 2.3% higher than that before infilling wells. This study can be used for reference in the development of similar reservoirs.

Research on Optimization of Reservoir Perforation Position in Offshore Polymer Flooding Oilfield

In order to enhance the effect of polymer flooding in offshore oilfields, so as to realize the longer stable production period and higher oil recovery, the reservoir perforation positions of production wells and injection wells are taken as research objects. By analyzing the distribution of remaining oil and production characteristics under different perforation positions, the optimum perforation positions of production wells and injection wells are selected. Bohai oilfield L was taken as target oilfield in this article, according to the actual reservoir characteristic parameters, three-dimensional laboratory physical simulation experiments of water flooding and polymer flooding were carried out, the experiments include different perforation positions of production wells and injection wells. The research result showed that the influence of perforation position on residual oil and development characteristics of the model is obvious. When takes the scheme of injection well upper part perforated and production well all part perforated, the least of the remaining oil distribution, the longest of the production period without water. Contrast with other perforation schemes, its stable production period increase about 1.2 times, the oil recovery of water flooding increase 3.7% - 6.0%, the oil recovery of polymer flooding increase 2.5% - 4.1%. So it is recommended as the best perforation scheme. Preferable effect had been achieved when translating research findings into practice. It can serve as a reference to the similar offshore oilfield.

Research and Application of Water Flooding Timing and Method for Blocky Bottom Water Fractured Buried Hill Reservoir

Oilfield A is a fractured buried hill reservoir in Bohai bay of China. In order to solve the difficult problem of water flooding timing and method in oilfield. Considering the characteristics of the buried hill fractures with stress sensitivity and strong heterogeneity, the ECLIPSE software was used in the research, and a three-dimensional injection-production numerical model for horizontal wells in buried hill reservoirs is established. According to the main research factors in water flooding, a series of water flooding schemes are designed, and the optimization of water flooding timing, oil recovery rate and water flooding mode in buried hill reservoirs were carried out. The results show that the optimum pressure level of fractured reservoir is about 70% of the original reservoir pressure. The optimal water flooding method is the conventional water flooding in the initial stage, when the water cut reaches 80%, it is converted into periodic water flooding. The oil recovery is the highest when the water injection period is 4 months. Field tests show that conventional water flooding is carried out in the initial stage of the oilfield A when the pressure is reduced to 70% of the original. Periodic water flooding is carried out when water cut is 80%. Good development results had been achieved in the 10 years since oilfield A was put into production. The average productivity of single well reached 300 m3/d in the initial stage, at present, the water cut is 60%, and the recovery degree is 18.5%, which is better than that of similar oilfields. This technology improves the water flooding effect of blocky bottom water fractured dual media reservoirs in metamorphic buried hills, and provides a reference for the development of similar reservoirs.

Vitamin D-binding protein in plasma microglia-derived extracellular vesicles as a potential biomarker for major depressive disorder

No well-established biomarkers are available for the clinical diagnosis of major depressive disorder(MDD).Vitamin D-binding protein(VDBP)is altered in plasma and postmortem dorsolateral prefrontal cortex(DLPFC)tissues of MDD patients.Thereby,the role of VDBP as a potential biomarker of MDD diagnosis was further assessed.Total extracellular vesicles(EVs)and brain cell-derived EVs(BCDEVs)were isolated from the plasma of first-episode drug-naïve or drug-free MDD patients and well-matched healthy controls(HCs)in discovery(20 MDD patients and 20 HCs)and validation cohorts(88 MDD patients and 38 HCs).VDBP level in the cerebrospinal fluid(CSF)from chronic glucocorticoid-induced depressed rhesus macaques or prelimbic cortex from lipopolysaccharide(LPS)-induced depressed mice and wild control groups was measured to evaluate its relationship with VDBP in plasma microglia-derived extracellular vesicles(MDEVs).VDBP was significantly decreased in MDD plasma MDEVs compared to HCs,and negatively correlated with HAMD-24 score with the highest diagnostic accuracy among BCDEVs.VDBP in plasma MDEVs was decreased both in depressed rhesus macaques and mice.A positive correlation of VDBP in MDEVs with that in CSF was detected in depressed rhesus macaques.VDBP levels in prelimbic cortex microglia were negatively correlated with those in plasma MDEVs in depressed mice.The main results suggested that VDBP in plasma MDEVs might serve as a prospective candidate biomarker for MDD diagnosis.

Insights on Chinese and European consensus for USgHIFU treatment of pancreatic cancer

The article“US-guided high-intensity focused ultrasound in pancreatic cancer treatment:a consensus initiative between Chinese and European HIFU centers”by Zhou et al.provides a valuable overview of the application of ultrasound-guided high-intensity focused ultrasound(USgHIFU)in treating pancreatic cancer(1).