A review on the balancing design of micro drills.

In recent years, micro-hole drilling with a diameter of less than 1 mm has been widely applied in electronic information, semiconductor, metal processing, and other fields. Compared with conventional drilling, the engineer problems that micro drills are more prone to suffer failure in advance have restricted further development of mechanical micro drilling. In this paper, the main substrate materials of micro drills were introduced. And two important technical means to improve properties of tool material, namely, grain refinement and tool coating, were also introduced, which are current main research directions of micro drills from the perspective of materials. The failure mechanisms of micro drills were briefly analyzed, mainly tool wear and drill breakage. In the structure of micro drills, cutting edges and chip flutes are directly related to tool wear and drill breakage, respectively. So the structural optimization and design of micro drills, especially for key structures such as cutting edges and chip flutes, have to face great challenges. Based on the above, two pairs of requirements for micro drills were proposed, that is, the balance between chip evacuation and drill stiffness and the balance between cutting resistance and tool wear. So some innovative schemes and related researches of micro drills regarding cutting edges and chip flutes were reviewed. Finally, a summary of micro drill design and existing problems and challenges is proposed.

Sorption of Monothioarsenate to the Natural Sediments and Its Competition with Arsenite and Arsenate.

Monothioarsenate (MTAsV) is one of the major arsenic species in sulfur- or iron-rich groundwater, and the sediment adsorption of MTAsV plays an important role in arsenic cycling in the subsurface environment. In this study, batch experiments and characterization are conducted to investigate the sorption characteristic and mechanism of MTAsV on natural sediments and the influences of arsenite and arsenate. Results show that MTAsV adsorption on natural sediments is similar to arsenate and arsenite, manifested by a rapid early increasing stage, a slowly increasing stage at an intermediate time until 8 h, before finally approaching an asymptote. The sediment sorption for MTAsV mainly occurs on localized sites with high contents of Fe and Al, where MTAsV forms a monolayer on the surface of natural sediments via a chemisorption mechanism and meanwhile the adsorbed MTAsV mainly transforms into other As species, such as AlAs, Al-As-O, and Fe-As-O compounds. At low concentration, MTAsV sorption isotherm by natural sediments becomes the Freundlich isotherm model, while at high concentration of MTAsV, its sorption isotherm becomes the Langmuir isotherm model. The best-fitted maximum adsorption capacity for MTAsV adsorption is about 362.22 µg/g. Furthermore, there is a competitive effect between MTAsV and arsenate adsorption, and MTAsV and arsenite adsorption on natural sediments. More specifically, the presence of arsenite greatly decreases MTAsV sorption, while the presence of MTAsV causes a certain degree of reduction of arsenite adsorption on the sediments before 4 h, and this effect becomes weaker when approaching the equilibrium state. The presence of arsenate greatly decreases MTAsV sorption and the presence of MTAsV also greatly decreases arsenate sorption. These competitive effects may greatly affect MTAsV transport in groundwater systems and need more attention in the future.

Plantago asiatica L. seeds extract protects against cardiomyocyte injury in isoproterenol- induced cardiac hypertrophy by inhibiting excessive autophagy and apoptosis in mice.

BACKGROUND: Cardiac hypertrophy is the early stage of many heart diseases, such as coronary heart disease, hypertension, valvular dysfunction and cardiomyopathy. Cardiomyocyte autophagy and apoptosis play an important role in the process of cardiac hypertrophic response. Plantago asiatica L. seeds extract (PASE) is prepared from a traditional herbal medicine in Asia with tremendous pharmacological activities. However, whether PASE could relieve cardiac hypertrophy has not been elucidated. The present study is aimed to investigate the effect of PASE on cardiac hypertrophy and explore its potential underlying mechanism. METHODS: Cardiac hypertrophy was induced in C57BL/6 mice by subcutaneous injection of isoproterenol (ISO) for two weeks. Meanwhile, the mice were intraperitoneally injected with PASE at dosages of 20, 40 and 80 mg/kg/day. Cardiac hypertrophy was evaluated by echocardiographic examination, haematoxylin and eosin staining and quantitative real-time polymerase chain reaction. Expressions of proteins involved in autophagy and apoptosis such as Beclin1, p62, LC3II, Bax, Bcl-2 and Cleaved-caspase-3 were detected by western blot analysis. Western blot, transient transfection, acridine orange staining, TUNEL staining and autophagy inducer were used to observe the effect and explore the mechanism of PASE on cardiomyocyte and H9c2 cells with excessive autophagy and apoptosis induced by ISO. RESULTS: ISO induction for two weeks disturbed the myocardial contractility and cardiac function of left ventricles of mice. PASE treated mice showed significantly improved cardiac function indexes, including EF, FS, SV and CO, compared with the ISO group. Treatment with PASE also decreased the heart weight/body weight ratio and cardiomyocyte size, and downregulated the mRNA and protein expressions of hypertrophic markers ANP, BNP, and ß-MHC. Furthermore, the changes of autophagy and apoptosis markers, such as LC3II, Beclin1, p62, Bcl-2, Bax and Cleaved-caspase-3 induced by ISO were resumed by PASE treatment. Consistently, PASE demonstrated similar effects on ISO-induced H9c2 cells as it did in vivo. In addition, PASE could counteract the increased autophagy induced by the autophagy inducer, rapamycin. CONCLUSION: PASE attenuated ISO-induced cardiac hypertrophy in mice by inhibiting excessive autophagy and apoptosis in cardiomyocytes. The novel findings may pave the way for the clinical usage of PASE for the prevention of heart diseases related with cardiac hypertrophy.

A Novel Pix2Pix Enabled Traveling Wave-Based Fault Location Method.

This paper proposes a new Image-to-Image Translation (Pix2Pix) enabled deep learning method for traveling wave-based fault location. Unlike the previous methods that require a high sampling frequency of the PMU, the proposed method can translate the scale 1 detail component image provided by the low frequency PMU data to higher frequency ones via the Pix2Pix. This allows us to significantly improve the fault location accuracy. Test results via the YOLO v3 object recognition algorithm show that the images generated by pix2pix can be accurately identified. This enables to improve the estimation accuracy of the arrival time of the traveling wave head, leading to better fault location outcomes.

[Adsorption of As(â ¢) in Water by Iron-loaded Graphene Oxide-Chitosan].

Based on the principle of self-assembly, graphene oxide, chitosan, and FeCl3·6H2O were mixed to prepare graphene oxide-chitosan coated iron-composite particles (Fe@ GOCS). Batch static experiments were carried out to investigate the kinetic and thermodynamic characteristics of As(Ⅲ) adsorption, and to identify the adsorption mechanism. Results showed that the iron on the GOCS was mainly in the form of α-FeO(OH). The As(Ⅲ) adsorption capacity increased with decreasing pH, and the highest adsorption capacity occurred at pH 3. After approximately 45 h, As(Ⅲ) adsorption reached equilibrium under the conditions of pH 3 and a temperature of 298.15, 308.15, and 318.15 K. The maximum adsorption capacity was 289.4 mg·g-1 for an optimal dosage of adsorbents of 1.0 g·L-1. After five times of repeated adsorption-desorption, the adsorption capacity increased slightly. The thermodynamic parameters showed that ΔGθ<0, ΔSθ > 0, and ΔHθ>0, thus indicating that As(Ⅲ) adsorption on Fe@GOCS was a spontaneous, endothermic, and entropy-increasing reaction, and that a higher temperature was more favorable for As(Ⅲ) adsorption. The pseudo-second-order model provided a good fit of the As(Ⅲ) adsorption kinetics for Fe@GOCS. Compared to the Langmuir isotherm, As(Ⅲ) adsorption experimental data fitted better to the Freundlich and Sips models. In combination with the characterization results, it was found that ion exchange and surface complexation were the main mechanisms of As(Ⅲ) removal from aqueous solution using Fe@GOCS.

[Characteristics and Influencing Factors of Monothioarsenate Adsorption on Goethite].

The adsorption kinetic of monothioarsenate (MTA) on goethite was characterized in this study, and batch experiments were then designed to further explore the effects of arsenate, arsenite, humic acid (HA), nitrate, and phosphate on the adsorption of MTA on goethite, and to identify the adsorption mechanism. The results showed that:① When a single arsenic species was present in a solution, the adsorption equilibrium times of MTA, arsenate, and arsenite on goethite were 8, 2, and 4 h, respectively. The adsorption experimental data of these three arsenic species were well fitted to a pseudo-second-order kinetic model. The equilibrium adsorption capacities (qe) of MTA, arsenate, and arsenite on goethite were 2129.851, 3291.838, and 1788.767 mg·kg-1, respectively. When MTA coexisted with arsenate or arsenite in a solution, MTA adsorption on goethite continued to be well fitted to a pseudo-second-order kinetic model. The value of qe for MTA was significantly reduced to 1236.941 mg·kg-1 when MTA coexisted with arsenate, and to 1532.287 mg·kg-1 when MTA coexisted with arsenite, due to the fact that arsenate and arsenite competed for adsorption sites with MTA. ② With an increase in HA concentration (10-50 mg·L-1), the qe of MTA decreased gradually, due to the fact that a large number of functional groups in HA preempted the surface adsorption sites of goethite with MTA. ③ When phosphate was added into the MTA solution, the qe values of MTA, arsenate, and arsenite on goethite were reduced greatly, to 492.802, 815.782, and 303.714 mg·kg-1, respectively, which was caused by the competitive adsorption of P and As. When nitrate was added into the MTA solution, the number of electron receptors and Eh of the solution increased, leading to the qe values of MTA, arsenate, and arsenite on goethite increasing to 2211.030, 3444.023, and 1835.537 mg·kg-1, respectively.

Lung cancer with concurrent EGFR mutation and ROS1 rearrangement: a case report and review of the literature.

ROS1 rearrangement has recently emerged as a new molecular subtype in non-small cell lung cancer, and is predominantly found in lung adenocarcinomas compared with other oncogenes such as EGFR, KRAS, or ALK. Patients who have both mutations are extremely rare. Here we report a 50-year-old female diagnosed with adenocarcinoma with sarcomatoid differentiation, who was shown to have EGFR and ROS1 mutations. The patient was treated surgically and received three cycles of adjuvant postoperative chemotherapy. In addition, we reviewed the previously reported cases and related literature. This presentation will provide further understanding of the underlying molecular biology and optimal treatment for non-small cell lung cancer patients with more than one driver mutation.