Nmr-VSM: Non-Touch Motion-Robust Vital Sign Monitoring via UWB Radar Based on Deep Learning.

In recent years, biometric radar has gained increasing attention in the field of non-touch vital sign monitoring due to its high accuracy and strong ability to detect fine-grained movements. However, most current research on biometric radar can only achieve heart rate or respiration rate monitoring in static environments, which have strict monitoring requirements and single monitoring parameters. Moreover, most studies have not applied the collected data despite their significant potential for applications. In this paper, we introduce a non-touch motion-robust vital sign monitoring system via ultra-wideband (UWB) radar based on deep learning. Nmr-VSM not only enables multi-dimensional vital sign monitoring under human motion environments but also implements cardiac anomaly detection. The design of Nmr-VSM includes three key components. Firstly, we design a UWB radar that can perform multi-dimensional vital sign monitoring, including heart rate, respiratory rate, distance, and motion status. Secondly, we collect real experimental data and analyze the impact of eight factors, such as motion status and distance, on heart rate monitoring. We then propose a deep neural network (DNN)-based heart rate data correction model that achieves high robustness in motion environments. Finally, we model the heart rate variability (HRV) of the human body and propose a convolutional neural network (CNN)-based anomaly detection model that achieves low-latency detection of heart diseases, such as ventricular tachycardia and ventricular fibrillation. Experimental results in a real environment demonstrate that Nmr-VSM can not only accurately monitor heart rate but also achieve anomaly detection with low latency.

Electron-rich benzofulvenes as effective dipolarophiles in copper(i)-catalyzed asymmetric 1,3-dipolar cycloaddition of azomethine ylides.

A series of benzofulvenes without any electron-withdrawing substituents were employed as 2π-type dipolarophiles for the first time to participate in Cu(i)-catalyzed asymmetric 1,3-dipolar cycloaddition (1,3-DC) reactions of azomethine ylides. An intrinsic non-benzenoid aromatic characteristic from benzofulvenes serves as a key driving force for activation of the electron-rich benzofulvenes. Utilizing the current methodology, a wide range of multi-substituted chiral spiro-pyrrolidine derivatives containing two contiguous all-carbon quaternary centers were formed in good yield with exclusive chemo-/regioselectivity and high to excellent stereoselectivity. Computational mechanistic studies elucidate the origin of the stereochemical outcome and the chemoselectivity, in which the thermostability of these cycloaddition products is the major factor.

Urchin-Like Structured MoO2 /Mo3 P/Mo2 C Triple-Interface Heterojunction Encapsulated within Nitrogen-Doped Carbon for Enhanced Hydrogen Evolution Reaction.

The development of highly efficient and cost-effective hydrogen evolution reaction (HER) catalysts is highly desirable to efficiently promote the HER process, especially under alkaline condition. Herein, a polyoxometalates-organic-complex-induced carbonization method is developed to construct MoO2 /Mo3 P/Mo2 C triple-interface heterojunction encapsulated into nitrogen-doped carbon with urchin-like structure using ammonium phosphomolybdate and dopamine. Furthermore, the mass ratio of dopamine and ammonium phosphomolybdate is found critical for the successful formation of such triple-interface heterojunction. Theoretical calculation results demonstrate that such triple-interface heterojunctions possess thermodynamically favorable water dissociation Gibbs free energy (ΔGH2O ) of -1.28 eV and hydrogen adsorption Gibbs free energy (ΔGH* ) of -0.41 eV due to the synergistic effect of Mo2 C and Mo3 P as water dissociation site and H* adsorption/desorption sites during the HER process in comparison to the corresponding single components. Notably, the optimal heterostructures exhibit the highest HER activity with the low overpotential of 69 mV at the current density of 10 mA cm-2 and a small Tafel slope of 60.4 mV dec-1 as well as good long-term stability for 125 h. Such remarkable results have been theoretically and experimentally proven to be due to the synergistic effect between the unique heterostructures and the encapsulated nitrogen-doped carbon.

Water-activated formation of porous graphitic carbon nitride with carbon vacancies to boost photocatalytic hydrogen peroxide production.

A facile water-activated method is developed for preparing porous graphitic carbon nitride with carbon vacancies by co-pyrolysis of melamine and water at a relatively low temperature under an Ar atmosphere, resulting in an increased specific surface area and the efficient separation of photo-generated electrons and holes. As expected, the optimal catalyst exhibited a high H2O2 yield of 180 µM within 4 h and good cycling stability. The reported template-free method may provide a reference for the preparation of high-performance photocatalysts in a facile way.

Stereodivergent Construction of 1,4-Nonadjacent Stereocenters via Hydroalkylation of Racemic Allylic Alcohols Enabled by Copper/Ruthenium Relay Catalysis.

An unprecedented hydroalkylation of racemic allylic alcohols and racemic ketimine esters enabled by Cu/Ru relay catalysis has been developed via merging the ruthenium-catalyzed asymmetric borrowing-hydrogen reaction with a copper-catalyzed asymmetric Michael addition in a one-pot procedure. The current method enables the efficient preparation of highly functionalized δ-hydroxyesters bearing 1,4-nonadjacent stereocenters in good yields with high levels of diastereoselectivity and excellent enantioselectivity under mild reaction conditions. The full complement of the four stereoisomers of hydroalkylation products could be readily accessed by orthogonal permutations of two chiral metal catalysts. The current work highlights the power of relay catalysis for the stereodivergent construction of 1,4-nonadjacent stereocenters that were otherwise inaccessible.

Catalytic Asymmetric Benzylation of Azomethine Ylides Enabled by Synergistic Lewis Acid/Palladium Catalysis.

The synergistic chiral Lewis acid/achiral Pd catalyst system was successfully applied in the enantioselective benzylation of various imine esters, giving a range of α-benzyl-substituted α-amino acid derivatives in satisfactory yield with excellent enantioselectivity. It is worth noting that this strategy exhibits good tolerance for bicyclic and monocyclic benzylic electrophiles. Furthermore, the utility of this synthetic protocol was demonstrated by the expedient preparation of enantioenriched antihypertensive drug α-methyl-l-dopa.

Selecting a stable solid form of remdesivir using microcrystal electron diffraction and crystal structure prediction.

Therapeutic options in response to the coronavirus disease 2019 (COVID-19) outbreak are urgently needed. In this communication, we demonstrate how to support selection of a stable solid form of an antiviral drug remdesivir in quick time using the microcrystal electron diffraction (MicroED) technique and a cloud-based and artificial intelligence implemented crystal structure prediction platform. We present the MicroED structures of remdesivir forms II and IV and conclude that form II is more stable than form IV at ambient temperature in agreement with experimental observations. The combined experimental and theoretical study can serve as a template for formulation scientists in the pharmaceutical industry.

Visual detection of miRNAs using enzyme-free amplification reactions and ratiometric fluorescent probes.

A visualized assay for miRNAs detection has been developed in this work. The presented method is based on a combination of enzyme-free amplification cascades of catalyzed hairpin assembly (CHA) and hybridization chain reaction (HCR) and fluorescence quenching of dual-emission ratiometric fluorescent probes (RF probes). MiRNAs can efficiently initiate enzyme-free amplification reactions (CHA and HCR) and produce the long nicked dsDNAs with a lot of glucose oxidases (GOD) on the surface of dynabeads bridged by the GOD-labeled hairpin DNA probes. Hydrogen peroxide (H2O2) is generated by oxidation of glucose catalyzed by GOD, which can quench the outer green fluorescence without affecting the internal red fluorescence of RF probes. Therefore, increased miRNA amount can result in change of the two fluorescence intensity ratios of RF probes with continuous color changes from green to red under a UV lamp, which can be easily recognized by naked eye. The proposed assay exhibits high sensitivity toward let-7a with dynamic range from 10-13 M to 10-8 M, and which is applied successfully to detecting let-7a in the small RNA samples.

Tunable pH-dependent oxygen evolution activity of strontium cobaltite thin films for electrochemical water splitting.

Understanding the oxygen evolution reaction (OER) dependence on the reaction environment pH is important to find alternative strategies to define an optimal pH value for high electrocatalytic activity. SrCoO2.5 films with the brownmillerite phase are investigated in this study for their strain effects on the OER activity, with particular regard to the pH dependence. Pulsed laser deposited films with different thicknesses and, thus, strain conditions, are characterized in terms of long range and near-order structural properties and electrochemical OER activity. By comparison, more strained thinner films have smaller OER current at lower pH conditions, but higher sensitivity to the environment pH. Spectroscopic measurements allow us to correlate such behaviors to the Co 3d-O 2p hybridization effects of the CoO6 octahedral sites, which lead to a variation of the 3d level electronic occupation. At the same time, density functional theory calculations show that the oxygen vacancy channels of the CoO4 tetrahedral sites are stable with respect to the strain effects. These results provide new perspectives to manipulate the pH dependent OER activity through the strain effects, useful for designing water splitting-based devices with optimized performances.

[Repair of traumatic metacarpophalangeal joint defect by metatarsophalangeal joint composite tissue flap autograft].

OBJECTIVE: To investigate the surgical method and effectiveness of repairing traumatic metacarpophalangeal joint defect by the composite tissue flap autograft of the second metatarsophalangeal joint. METHODS: Between June 2005 and December 2009, 6 cases (6 fingers) of traumatic metacarpophalangeal joint defect were treated with the composite tissue flap autograft of second metatarsophalangeal joint (containing extensor tendon, flexor tendon, proper digital nerve, planta or dorsal flap). All patients were males, aged 18-48 years, including 3 cases of mechanical injury, 2 cases of crush injury, and 1 case of penetrating trauma. The 2nd, 3rd, and 4th metacarpophalangeal joints were involved in defects in 2 cases, respectively, and defects ranged from 1.5 cm x 1.5 cm to 3.0 cm x 2.5 cm in size. All patients had skin and soft tissue defects, and defects ranged from 4 cm x 2 cm to 5 cm x 4 cm in size; and 5 cases complicated by extensor tendon defect (2.5-5.0 cm in length), 3 cases by flexor tendon rupture, and 3 cases by common palmar digital nerve injury. The time from injury to admission was 2-6 hours. RESULTS: The composite tissue flaps and skin grafts survived in all cases. All incisions healed by first intention. All patients were followed up 1-5 years. The X-ray films showed good healing between the transplanted metatarsophalangeal joint and metacarpals and phalanges at 9-14 weeks postoperatively. The appearance, colour, and texture of the skin flap were satisfactory, and the senses of pain and touch were recovered. The palmar flexion range of transplanted metacarpophalangeal joints was 50-70 degrees, and the dorsal extension range was 5-10 degrees at last follow-up. According to the functional assessment criteria of upper limb formulated by the Hand Surgery Branch of Chinese Medical Association, the results were excellent in 4 cases, good in 1 case, and fair in 1 case, and the excellent and good rate of 83.3%. No dysfunction of the donor foot was observed. CONCLUSION: The metatarsophalangeal joint composite tissue flap can provide bone, nerve, skin, muscles, and tendons, so it is an effective approach to repair the metacarpophalangeal joint defect and to recover the function of the injured joints in one operation.

[Repair and reconstruction of traumatic defect of medial malleolus in children].

OBJECTIVE: To investigate the operative method and clinical effect of repairing and reconstructing the traumatic defect of medial malleolus in children with complex tissue flap of vascularized fibular head epiphysis. METHODS: From July 2003 to December 2007, 8 children with defect of medial malleolus due to wheel injury were treated, including 5 boys and 3 girls aged 2-10 years old. The medial malleolus were completely defected (5 cases at left foot and 3 cases at right foot) and combined with the skin defect around the medial malleolus (4.0 cm x 2.0 cm - 9.5 cm x 5.5 cm). The time from injury to hospital admission was 6-8 hours in 2 cases, and 24-168 hours in 6 cases. The complex of vascularized fibular head epiphysis and tissue flap was adopted to repair the defect. The flap 4.5 cm x 2.5 cm - 10.0 cm x 6.0 cm in size and the fibular head epiphysis 2.5-3.0 cm in length were harvested. The donor site was sutured directly. RESULTS: All wounds healed by first intention, all the composite tissue flap survived with good blood circulation, all the epiphysis of medial malleolus healed within 6-9 weeks, and all the donor sites healed well. All the child patients were followed up for 1-5 year. The color and elasticity of the flaps were good, without cicatricial contracture. The patients had no inversion of ankle joint, with satisfying loading and walking function. Six cases had normal flexion and extension of the ankle and 2 cases were limited slightly (dorsiflexion 10-20 degrees, plantarflexion 35 degrees). Talus has no inner move and ankle joint had no eversion. Seven cases were graded as excellent and 1 as good according to the standard of American Orthopaedic Foot & Ankle Society. For the medial malleolus, no premature closure of epiphysis occurred, and the center of ossification grew gradually and well developed like the contralateral side. The donor knee joint had normal flexion and extension function, without inversion and instability. CONCLUSION: The complex of vascularized fibular head epiphysis and tissue flap can repair the epiphysis and soft tissue defect of medial malleolus in children at one stage, and the reconstructed medial malleolus can develop with the growth of children. It is a satisfactory method of reconstructing the traumatic defect of medial malleolus in children.

[Chinese herbs application combined with operation for treating post-traumatic tibial osteomyelitis complicated with bone-skin defects].

OBJECTIVE: The aim of this study was to explore the method and clinical effects of integration of Chinese herbs and operation for the treatment of post-traumatic tibial osteomyelitis complication with bone-skin defect. METHODS: Among 28 patients with post-traumatic tibial osteomyelitis complicated with bone-skin defects, 18 patients were male and 10 females, ranging in age from 18 to 68 years, with an average of 32.5 years. All the patients were treated with transplantation of free iliac flaps to one-stage repair the bone-skin defects after infection controlled with Chinese herbs dressing. The curative effects were analyzed. RESULTS: All the patients were followed up and ranged from 8 to 56 months, with an average of 30 months. All of the flap survived, and the wounds got primary healing in 26 patients and secondary healing in 2 patients. All the grafted bone united in 2 to 14 months,with a mean time of 4.6 months. The osteomyelitis recurred in 2 patients and got healed by focal debridement. CONCLUSION: Chinese herbs application combined with operation for treating post-traumatic tibial osteomyelitis complicated with hone-skin defects is effective to control infection, one-stage repair the tissue defects, which is worthy popularizing.

[Free iliac flap grafting for repair of tibia traumatic osteomyelitis complicated with bone-skin defect].

OBJECTIVE: To investigate the method and clinical effect of free iliac flap grafting in repairing the tibia traumatic osteomyelitis complicated with bone-skin defect. METHODS: From June 2001 to February 2006, 28 patients with tibia traumatic osteomyelitis complicated with bone-skin defect were treated with free iliac flap grafting at stage I. There were 18 males and 10 females, with an average of 32.5 years(18-68 years). There were traffic injury in 11 cases, bruise in 6 cases, explosive injury in 5 cases, machinery injury in 4 cases, and falling injury in 2 cases. The disease courses of patients were 1-6 months. All patients had been treated by 2-6 operations. The wounds located at the mid and upper tibia in 13 cases, and the inferior tibia in 15 cases. The length of free iliac was 0.5-6.0 cm and the size of the flap ranged from 4.5 cm x 3.5 cm to 28.0 cm x 16.0 cm. The external fixation were applied in 18 cases, and steel plate were applied in 10 cases. The donor sites were sutured directly. RESULTS: All of the flaps survived completely. The wounds healed by first intention in 26 cases and by second intention in 2 cases. The donor sites healed by first intention. Twenty-eight patients were followed up for 6 to 56 months (mean, 30 months). The appearances of the flaps were satisfactory and the colour was similar to recipient site. All grafted bone united 2-14 months (mean, 4.6 months) after operation according to X-ray examination. In 20 patients who did not achieved union before operation, fracture healed 2 to 6 months after operation(mean, 3.2 months). Osteomyelitis recurred 12 months after operation in 2 cases and healed by nidus clearing. CONCLUSION: Free iliac flap which used to repair tibia traumatic osteomyelitis complicated with bone-skin defect, can repair the defect at stage I and enhance the anti-infectious ability. It is one of appropriate and effective clinical methods.