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Here, we report a nickel-catalyzed enantioconvergent hydroalkylation of olefins with trifluoromethyl-containing α-alkyl halides for the synthesis of enantioenriched trifluoromethylated alkanes. This reaction employs readily available and bench-stable alkenes as alkyl coupling partners, featuring mild conditions, a broad substrate scope, and high functional group tolerance. The synthetic utility of this method is further demonstrated in the late-stage functionalization of a range of drug molecules and natural products.

Solar energy has the potential to be the next-generation power source if the intermittent nature can be overcome through rational energy storage engineering. The competitiveness of solar rechargeable batteries can...

With the continuous progress of the aging process, the prevalence of chronic diseases and disability among the elderly increases, resulting the corresponding medical demand and medical costs create an intensified pressure on the healthcare infrastructures. To this end, this topic proposes a remote health risk prediction model for the community- and home-based scenarios based on wearable sensor technology and deep learning technology to alleviate the pressure on healthcare infrastructure. The model is designed in three functional considerations. The wearable sensor component is responsible for remotely and continuously collecting vital signs of the elderly, including five variables: systolic blood pressure (SBP), heart rate (HR), respiratory rate (RR), temperature (TEMP), and oxygen saturation (SPO2). The neural network component consists of five different 5- input-1-output Long Short-Term Memory (LSTM) networks, which are responsible for predicting values of the vital signs. The risk prediction component consists of a simplified version of the National Early Warning Score (NEWS), which is responsible for predicting the health risk level based on the predicted values of vital signs. The model is developed and tested using existing electronic health record (EHR) that mimic vital signs data collected via wireless sensor network. We found that the model performed the best using a dataset in a size of 1000 admissions, within a time window of 12 hours, and with a configuration of 5 neurons and 50 epochs. The accuracy was over 74% for the risk level calculated from the predicted values of vital signs. Our results suggest that remote monitoring and prediction of health risks in the elderly using deep learning models is a feasible new strategy for community- and home-based monitoring systems.

Some patients with colon cancer eventually develop metastasis during treatment, and the 5‑year survival rate of patients with metastatic colon cancer remains relatively low, which is most likely due to the ineffectiveness of the current standard treatment. Systemic treatment for patients with colon cancer has expanded from chemotherapy to targeted therapy and immunotherapy. Immunotherapy holds promise in the treatment of colon cancer. The present study revealed the role of innate immune receptor helicase DExD/H‑box helicase 58 (DDX58), which encodes retinoic acid‑inducible gene‑I (RIG‑I), in colon cancer. It was demonstrated that colon cancer patients with a low protein expression of DDX58/RIG‑I had a worse 5‑year survival rate of patients compared with patients with a high expression of DDX58/RIG‑I. The activation of DDX58/RIG‑I inhibited the proliferation, migration and invasion of colon cancer cells, as well as tumor growth in a nude mouse xenograft model of colon cancer. To investigate the mechanisms of action of DDX58/RIG‑I in colon cancer, the role of signal transducer and activator of transcription 3 (STAT3)/cystathionine‑γ‑lyase (CSE) signaling in the up‑ or downregulation of DDX58 was examined. The data demonstrated that DDX58 regulated the STAT3/CSE signaling pathway by interacting with STAT3 and consequently affecting the proliferation of tumor cells in colon cancer. In addition, the RIG‑I agonist, SB9200, induced proliferation, migration and invasion of human colon cancer. On the whole, the present study demonstrates that DDX58/RIG‑I affects the proliferation of tumor cells by regulating STAT3/CSE signaling in colon cancer. The findings presented herein suggest that DDX58/RIG‑I activation may be an effective treatment strategy, and DDX58/RIG‑I agonists may be potential therapeutic candidates for colon cancer.

Li metal is an ideal anode for next-generation batteries because of its high theoretical capacity and low potential. However, the unevenly distributed stress in Li metal anodes (LMAs) induced by volume fluctuation may cause the electrode to fracture easily, especially during high-rate plating/stripping processes. Here fracture-resistant LMAs using the concept of bulk nanostructured materials are designed via a metallurgical process. In bulk nanostructured Li (BNL), ionic conducting phases exist at grain boundaries, which promote Li+ transport. The refined Li grain size and precipitation hardening in BNL enhances the mechanical strength and fatigue endurance, alleviating the unevenly distributed stress and preventing electrode pulverization. Density functional theory is used to investigate the binding energy between Li and various kinds of oxides and SiO2 is found to be optimal additive among screened oxides. BNL has 91% of the theoretical capacity of Li metal. In full cells with BNL anode, LiFePO4 could deliver capacity of 90 mAh g-1 at 10C, an order of magnitude higher than that in full cells with Li foil anode. This strategy is expected to pave the way for fracture-resistant LMAs in high-rate cycling with maximum capacity.

Li metal is considered to be an ultimate anode for metal batteries owing to its extremely high theoretical capacity and lowest potential. However, numerous issues such as short lifespan and infinite volume expansion caused by the dendrite growth during Li plating/stripping hinder its practical usage. These challenges become more grievous under high current densities. Herein, 3D porous MXene aerogels are proposed as scaffolds for high-rate Li metal anodes using Ti3 C2 as an example. With high metallic electron conductivity, fast Li ion transport capability, and abundant Li nucleation sites, such scaffolds could deliver high cycling stability and low overpotential at current density up to 10 mA cm-2 . High rate performance is also demonstrated in full cells with LiFePO4 as cathodes. This work provides a new type of scaffolds for Li metal anodes and paves the way for the application of non-graphene 2D materials toward high energy density Li metal batteries.

We evaluate the ablation thresholds of Er:YAG and Er,Cr:YSGG laser for enamel and dentin. A total of 140 dental slices is evenly divided into two groups: the dentin group and the enamel group. Dental tissues are irradiated with either an Er:YAG laser or an Er,Cr:YSGG laser with pulse widths in the order of 100 μs. The laser fluence is increased gradually until the ablation crater is formed. The laser ablation threshold is calculated using probit analysis. The ablation thresholds of the Er:YAG laser for dentin and enamel range from 2.88 to 3.36 J/cm2 and from 2.94 to 3.8 J/cm2, respectively, and the ablation thresholds of the Er,Cr:YSGG laser for dentin and enamel range from 2.92 to 4.2 J/cm2 and from 4.93 to 5.66 J/cm2, respectively.

Objective To explore the influence of the exogenous Jaagsiekte sheep retrovious (exJSRV) envelope protein (Env) on NIH3T3 cell proliferation. Methods A recombinant plasmid pcDNA4/myc-His/exJSRV- env carrying exJSRV- env gene was constructed, and then the correctness of the recombinant plasmid was identified by PCR, restriction enzyme digestion and sequencing. The recombinant plasmid pcDNA4/myc-His/exJSRV- env was transiently transfected into NIH3T3 cells by Lipofectamine(TM) LTX. After the transfection of the recombinant plasmid, the expression of exJSRV- env was detected by reverse transcription PCR and Western blotting. The effect of Env on cell proliferation was investigated by CCK-8 assay and plate colony formation assay. Results The recombinant eukaryotic expression plasmid containing exJSRV- env was successfully constructed as identified by PCR, restriction enzyme identification and sequencing. After the recombinant plasmid was transiently transfected into NIH3T3 cells, reverse transcription PCR and Western blotting showed the expression of exJSRV- env , and Env promoted NIH3T3 cell proliferation significantly. Conclusion JSRV Env was expressed successfully in the NIH3T3 cells and promoted the proliferation of NIH3T3 cells.

With the characteristics of input nonlinearity, time-varying parameters and the couplings between main and tail rotor, it is difficult for the yaw dynamics of Rotorcraft to realize good tracking performance while maintaining stability and robustness simultaneously. In this paper, a new kind of robust controller design strategy based on active modeling technique is proposed to attenuate the uncertainties pre-described in the yaw control of unmanned systems. Firstly, by detailed analysis, the uncertainties are introduced into the new-designed yaw dynamics model by using the concept of modeling errors. Then, Kalman filter is used to estimate the modeling errors simultaneously, which is used subsequently to design the robust controller. Finally, the new strategy is tested with respect to the unmanned Rotorcraft system to show the feasibility and validity of it.

In clinical practice, laser ablation usually works under liquid environment such as water, blood or their mixture. Laser-induced vapor bubble or bubble formation and its consequent dynamics were believed to have important influence on tissue ablation. In the paper, the dynamic process of vapor bubble formation and consequently collapse induced by pulsed Ho:YAG laser in static water was investigated by using high-speed camera. The results showed that vapor channel / bubble can be produced with pulsed Ho:YAG laser, and the whole dynamic process of vapor bubble formation, pulsation and consequently collapse can be monitored by using high-speed camera. The dynamic characteristics of vapor bubble, such as pulsation period, the maximum depth and width were determined. The dependence of above dynamic parameters on incident radiant exposure was also presented. Based on which, the influence of vapor bubble on hard tissue ablation was discussed.

To evaluate the whole process of demineralization and remineralization in human dentin using Raman spectroscopy (RS).Human molars from Chinese subjects were cut into tooth sections and painted with an acid-resistant varnish leaving one dentin surface exposed. The tooth sections were immersed in 0.3% citric acid to simulate the oral natural demineralization and were randomly divided into three groups with a sample size of n=12 each: 10 min (I), 20 min (II), and 40 min (III), according to the acid etch time. Then all the samples were submitted to a remineralizing solution for 5 days. The Raman spectra were measured before and after each treatment.The result showed that although there was no new constituent formed in the whole process, the peak intensities of inorganic constituents decreased with the increase of acid etch time, while the trend of the organic constituents were the opposite. After remineralization, the peak intensities of inorganic constituents increased again.In conclusion, using RS it would be possible to efficiently monitor the demineralization and remineralization status of human dentin.

Water plays an important role in laser ablation. There are two main interpretations of laser-water interaction: hydrokinetic effect and vapor phenomenon. The two explanations are reasonable in some way, but they can’t explain the mechanism of laser-water interaction completely. In this study, the dynamic process of vapor channel formation induced by pulsed CO 2 laser in static water layer was monitored by high-speed camera. The wavelength of pulsed CO 2 laser is 10.64 um, and pulse repetition rate is 60 Hz. The laser power ranged from 1 to 7 W with a step of 0.5 W. The frame rate of high-speed camera used in the experiment was 80025 fps. Based on high-speed camera pictures, the dynamic process of vapor channel formation was examined, and the threshold of vapor channel formation, pulsation period, the volume, the maximum depth and corresponding width of vapor channel were determined. The results showed that the threshold of vapor channel formation was about 2.5 W. Moreover, pulsation period, the maximum depth and corresponding width of vapor channel increased with the increasing of the laser power.

To examine the temperature changes in the pulp chamber during cavity preparation in dentin with the Er:YAG laser (2940 nm), a total 20 intact premolars teeth were divided into 4 groups for dentin ablation with different radiant exposures at 4Hz and 8Hz with and without water spray. A K-type thermocouple was used to monitor the temperature changes in pulp chamber during laser treatment. The total time of irradiation was 70 sec. the water spray rate was 3 mL/min. It showed that maximum temperature rise increases with the increasing of radiant exposure and pulse repetition rate and the additional water cooling during laser ablation can significantly reduce the temperature rise in pulp chamber which will benefit to avoid or reduce thermal damage to tooth structure and dental pulp. The highest rise of temperature in the pulp was achieved with 20 J/cm 2 and 8 Hz (19.83°C ). For all sample without water spray, the rise of temperature was exceed 5 °C . In contrast, with water spray, the temperature rise in the pulp can be firmly controlled under 1°C. The results also indicated that ablation rate and efficiency can be enhanced by increasing the incident radiant exposure and pulse repetition rate, which simultaneously producing more heat accumulation in dental tissue and causing thermal damage to dental tissue. By applying an additional water spray, thermal damage can be significantly reduced in clinical application.

The aim of this study is to evaluate the demineralization process in human dentine using Raman spectroscopy (RS). Nine human molars from Chinese subjects were cut into twelve tooth sections. The sections were painted with an acidresistant varnish leaving one dentine surface exposed and then immersed into 0.3% citric acid to simulate the oral natural demineralization. According to the acid-etch time, specimens were randomly divided into four groups: Ⅰ5 min, Ⅱ 10 min, Ⅲ 20 min and Ⅳ 40 min. Raman spectra were measured before and after each treatment. The result showed that no new bands, bands shifts, or disappearance of bands occurred in the whole process. However, the peak intensities of inorganic constituents decreased with the increase of acid-etch time, while the trends of organic constituents were opposite. In conclusion, RS could be able to efficiently monitor the demineralization status of human dentine.