A self-powered intracardiac pacemaker in swine model.

Harvesting biomechanical energy from cardiac motion is an attractive power source for implantable bioelectronic devices. Here, we report a battery-free, transcatheter, self-powered intracardiac pacemaker based on the coupled effect of triboelectrification and electrostatic induction for the treatment of arrhythmia in large animal models. We show that the capsule-shaped device (1.75 g, 1.52 cc) can be integrated with a delivery catheter for implanting in the right ventricle of a swine through the intravenous route, which effectively converts cardiac motion energy to electricity and maintains endocardial pacing function during the three-week follow-up period. We measure in vivo open circuit voltage and short circuit current of the self-powered intracardiac pacemaker of about 6.0 V and 0.2 µA, respectively. This approach exhibits up-to-date progress in self-powered medical devices and it may overcome the inherent energy shortcomings of implantable pacemakers and other bioelectronic devices for therapy and sensing.

A Ti3C2 MXene-integrated near-infrared-responsive multifunctional porous scaffold for infected bone defect repair.

Infected bone defect repair has long been a major challenge in orthopedic surgery. Apart from bacterial contamination, excessive generation of reactive oxygen species (ROS), and lack of osteogenesis ability also threaten the defect repair process. However, few strategies have been proposed to address these issues simultaneously. Herein, we designed and fabricated a near-infrared (NIR)-responsive, hierarchically porous scaffold to address these limitations in a synergetic manner. In this design, polymethyl methacrylate (PMMA) and polyethyleneimine (PEI) were used to fabricate the porous PMMA/PEI scaffolds via the anti-solvent vapor-induced phase separation (VIPS) process. Then, Ti3C2 MXenes were anchored on the scaffolds through the dopamine-assisted co-deposition process to obtain the PMMA/PEI/polydopamine (PDA)/MXene scaffolds. Under NIR laser irradiation, the scaffolds were able to kill bacteria through the direct contact-killing and synergetic photothermal effect of Ti3C2 MXenes and PDA. Moreover, MXenes and PDA also endowed the scaffolds with excellent ROS-scavenging capacity and satisfying osteogenesis ability. Our experimental results also confirmed that the PMMA/PEI/PDA/MXene scaffolds significantly promoted new bone formation in an infected mandibular defect model. We believe that our study provides new insights into the treatment of infected bone defects.

Hierarchically Porous Implants Orchestrating a Physiological Viscoelastic and Piezoelectric Microenvironment for Bone Regeneration.

The extracellular matrix microenvironment of bone tissue comprises several physiological cues. Thus, artificial bone substitute materials with a single cue are insufficient to meet the demands for bone defect repair. Regeneration of critical-size bone defects remains challenging in orthopedic surgery. Intrinsic viscoelastic and piezoelectric cues from collagen fibers play crucial roles in accelerating bone regeneration, but scaffolds or implants providing integrated cues have seldom been reported. In this study, it is aimed to design and prepare hierarchically porous poly(methylmethacrylate)/polyethyleneimine/poly(vinylidenefluoride) composite implants presenting a similar viscoelastic and piezoelectric microenvironment to bone tissue via anti-solvent vapor-induced phase separation. The viscoelastic and piezoelectric cues of the composite implants for human bone marrow mesenchymal stem cell line stimulate and activate Piezo1 proteins associated with mechanotransduction signaling pathways. Cortical and spongy bone exhibit excellent regeneration and integration in models of critical-size bone defects on the knee joint and femur in vivo. This study demonstrates that implants with integrated physiological cues are promising artificial bone substitute materials for regenerating critical-size bone defects.

Analysis for discharge within 2 days after thoracoscopic anatomic lung cancer surgery.

OBJECTIVES: The risk and beneficial factors of early discharge after thoracoscopic anatomic lung cancer surgery are unknown, and this study aims to investigate predictors and associated 30-day readmission for early discharge. METHODS: We performed a single-center retrospective analysis of 10,834 consecutive patients who underwent thoracoscopic anatomic lung cancer surgery. Two groups were determined based on discharge date: "discharged by postoperative Day 2" and "discharged after postoperative Day 2." Univariable and multivariable analysis were conducted to identify predictors for discharge. Using propensity score matching (PSM) to compare 30-day readmission rate between two cohorts. RESULTS: A total of 1911 patients were discharged by postoperative Day 2. Multivariable analysis identified older age (odds ratio (OR) = 1.014, p < 0.001), male sex (OR = 1.183, p = 0.003), larger tumor size (OR = 1.248, p < 0.001), pleural adhesions (OR = 1.638, p = 0.043), lymph nodes calcification (OR = 1.443, p = 0.009), advanced clinical T stage (vs. T < 2, OR = 1.470, p = 0.010), lobectomy resection (vs. segmentectomy resection, OR = 2.145, p < 0.001) and prolonged operative time (OR = 1.011, p < 0.001) as independent risk factors for discharge after postoperative Day 2. Three adjustable variables including higher FEV1 /FVC (OR = 0.989, p = 0.001), general anesthesia (GA) plus thoracic paravertebral blockade (vs. GA alone, OR = 0.823, p = 0.006) and uni-portal thoracoscopic surgery (vs. multi-portal, OR = 0.349, p < 0.001) were associated with a decreased likelihood of discharge after postoperative Day 2. Before and after a 1:1 PSM, discharged by postoperative Day 2 did not increase the risk of 30-day readmission compared to counterparts. CONCLUSIONS: Carefully selected patients can be safely discharged within 2 days after thoracoscopic anatomic lung cancer surgery. Three modifiable variables may be favorable for promoting discharge by postoperative Day 2.

High-Performance Flexible Sulfur Cathodes with Robust Electrode Skeletons Built by a Hierarchical Self-Assembling Slurry.

The electrochemical performance of lithium-sulfur batteries is fundamentally determined by the structural and mechanical stability of their composite sulfur cathodes. However, the development of cost-effective strategies for realizing robust hierarchical composite electrode structures remains highly challenging due to uncontrollable interactions among the components. The present work addresses this issue by proposing a type of self-assembling electrode slurry based on a well-designed two-component (polyacrylonitrile and polyvinylpyrrolidone) polar binder system with carbon nanotubes that forms hierarchical porous structures via optimized water-vapor-induced phase separation. The electrode skeleton is a highly robust and flexible electron-conductive network, and the porous structure provides hierarchical ion-transport channels with strong polysulfide trapping capability. Composite sulfur cathodes prepared with a sulfur loading of 4.53 mg cm-2 realize a very stable specific capacity of 485 mAh g-1 at a current density of 3.74 mA cm-2 after 1000 cycles. Meanwhile, a composite sulfur cathode with a high sulfur loading of 14.5 mg cm-2 in a lithium-sulfur pouch cell provides good flexibility and delivers a high capacity of 600 mAh g-1 at a current density of 0.72 mA cm-2 for 78 cycles.

Complete mitochondrial genome of Proisotoma minuta (Collembola: Proisotominae).

The springtail Proisotoma minuta is a cosmopolitan species that can be found in many different habitats, especially in soil ecosystems. It is considered to be a good indicator of soil health. In this study, mitogenome information was obtained, which could lay a foundation for future fauna studies. The mitogenome of P. minuta is a circular module of 15,930 bp, including 13 protein-coding genes, 22 transfer RNA genes, and 2 ribosomal RNA genes. The mitogenome of P. minuta is composed of 35.9% A, 28.5% T, 13.7% G, and 21.3% C. Phylogenetic analysis revealed that P. minuta was well grouped in the subfamily Proisotominae and had a closer relationship with Anurophorinae than Isotominae subfamily and other families.

Regulating Polysulfide Diffusion and Deposition via Rational Design of Core-Shell Active Materials in Li-S Batteries.

Polar host materials with strong adsorption capacity of polysulfides are designed to limit the shuttle effect in sulfur cathodes. However, a critical problem is to control diffusion and deposition of lithium polysulfides during cycling, which significantly impacts cycling stability and sulfur utilization. Here, we report using a sequential adsorption-guided self-assembly to design two types of core-shell sulfur particles with opposite polysulfide adsorption gradients to explore quantitatively the regulation of polysulfide diffusion and deposition. We show that a positive core-shell design of sulfur particles (PCSD@SP), i.e., polysulfide adsorption capability decreasing from the interior to the exterior of the host, is more effective in restricting polysulfide diffusion and regulating polysulfide deposition than the negative core-shell counterpart (NCSD@SP). As a result, the PCSD@SP electrode with a sulfur loading of 7 mg cm-2 exhibits a stable areal capacity of 6 mAh cm-2 over 130 cycles at 0.2C. At intermittent discharge/charge, the PCSD@SP electrode retains excellent stability compared with the NCSD@SP. We conclude that rational design of positive core-shell active materials can be used to regulate polysulfide diffusion and deposition to boost electrochemical reaction dynamics and performance. The reported findings will be of immediate benefit to a range of researchers in the design of high-performance lithium-sulfur batteries.

Mechanistically Scoping Cell-Free and Cell-Dependent Artificial Scaffolds in Rebuilding Skeletal and Dental Hard Tissues.

Rebuilding mineralized tissues in skeletal and dental systems remains costly and challenging. Despite numerous demands and heavy clinical burden over the world, sources of autografts, allografts, and xenografts are far limited, along with massive risks including viral infections, ethic crisis, and so on. Per such dilemma, artificial scaffolds have emerged to provide efficient alternatives. To date, cell-free biomimetic mineralization (BM) and cell-dependent scaffolds have both demonstrated promising capabilities of regenerating mineralized tissues. However, BM and cell-dependent scaffolds have distinctive mechanisms for mineral genesis, which makes them methodically, synthetically, and functionally disparate. Herein, these two strategies in regenerative dentistry and orthopedics are systematically summarized at the level of mechanisms. For BM, methodological and theoretical advances are focused upon; and meanwhile, for cell-dependent scaffolds, it is demonstrated how scaffolds orchestrate osteogenic cell fate. The summary of the experimental advances and clinical progress will endow researchers with mechanistic understandings of artificial scaffolds in rebuilding hard tissues, by which better clinical choices and research directions may be approached.

Tailoring Crystalline Morphology by High-Efficiency Nucleating Fiber: Toward High-Performance Poly(l-lactide) Biocomposites.

In this work, a high-melting-point poly(l-lactide) fiber (hPLLA fiber) with high-efficiency nucleation activity was prepared and introduced into PLLA matrix to prepare fully biodegradable PLLA biocomposites. The highly active nucleating surfaces of the hPLLA fiber induced chain ordering and lamellar organization, leading to a preferable formation of well-organized PLLA transcrystallinity at the surface of the hPLLA fiber under quiescent conditions. The construction of such compact transcrystallinity increased the crystallinity and enhanced the interfacial adhesion, which largely promoted heat resistance, tensile strength, and barrier property of PLLA biocomposites at a low content of hPLLA fiber. With the addition of 1 wt % hPLLA fiber, the storage modulus of the PLLA biocomposite was enhanced by 82 times from 4 to 330 MPa at 80 °C and the oxygen permeability coefficient and water permeability coefficient were decreased by 52 and 51% to be 5.9 × 10-15 cm3·cm/cm2·s·Pa and 4.5 × 10-14 g·cm/cm2·s·Pa, respectively, compared with those of pure PLLA. Moreover, the transparency of PLLA was maintained with the incorporation of hPLLA fiber. Thus, this strategy paved a new way to prepare high-performance and fully biodegradable biocomposites.

[Sero-epidemiological survey on general community population to understand the infection status after the first wave of pandemic 2009 H1N1 influenza in Guangdong province].

OBJECTIVE: To understand the infection status of pandemic 2009 H1N1 influenza after the first epidemic wave and to estimate the infected population. METHODS: Multi-stage stratified random sampling was introduced with 4500 subjects chosen in Guangdong province. 1500 people were selected from 5 districts (3 streets were selected in every district) in Guangzhou city which was representing the large cities. 1500 people were respectively selected from medium-sized city and rural areas, including 20 cities (1 county or district was selected in every city, at least 1 street or town was selected in every county or district respectively and then 1 - 2 residential area or county was selected in every street or township, respectively). Every sample was selected in accordance with the principle of random sampling, excluding those who had injected with novel H1N1 vaccine. We used hemagglutination inhibition test to understand the serum antibody level of novel H1N1, with title of 1:40 as positive. RESULTS: A number of 4319 specimens, distributed in 21 cities, 25 counties, 85 streets or townships, 144 residential areas, were tested, with an overall positive rate as 22.82% (985/4319). The positive rate of those who had no symptoms of cold since June was 23.47% (471/2007). The positive rate of those who had fever, cough or sore throat was 26.25% (714/2720). The positive rate of those who had influenza-like illness (ILI) was 29.69% (337/1135). CONCLUSION: The infection rate in the first epidemic wave of the novel influenza A (H1N1) pandemic in Guangdong province was 22.82% (985/4317). Based on the number of residents in Guangdong province, the number of natural was estimated to have reached 21.78 million.

[Investigation of a norovirus outbreak through contaminated centralized water supply system].

OBJECTIVE: To investigate the etiology and source of an infectious diarrhea outbreak and control the epidemic. METHODS: Through the retrospective cohort study, we had surveyed all the residents who complained symptoms of diarrhea or vomiting since Nov. 20th,2007 from the five villages in the north of town Y, and collected hygiene information on the water supply system of the five villages, the environment information of three villages and hygiene information of some case-indexed families, and tested the etiological biomarker, including nucleoside acid of norovirus through Real-time PCR and nested PCR technologies. RESULTS: From Nov. 24th to Dec. 3th in 2007, 435 diarrhea or vomiting cases were found in the north of Y town, where tap water A was supplied for daily use. The attack rate was 12.93%. The diarrhea cases were distributed among all country groups who has used tap water A and the attack rate was ranged from 5.21% (20/384) to 21.23% (100/471). Drinking the tap water A was significantly associated with an increased risk of infection (RR = 9.246, 95% CI: 6.25 -13.68). About 85.9% (262/ 305) of the cases were from Nov. 25th to 27th. An investigation of a country of S2 group showed that the incidence of different age groups was distributed as the following: 0 - year-old 20.0% (3/15); 10 - year-old 17.3% (9/52); 20 - year-old 15.2% (16/105); older than 60 year-old 23.3% (7/30). No statistical significance was identified between age and infection(chi2 = 1.15, P >0.05). Most of the patients were not serious and well prognostic, and no hospitalized or dead cases were reported. On site investigation and daily water quality monitoring showed that disinfection procedures were not strictly followed. The monitoring data also indicated the bacteriology index of tap water A was disqualified. The test of Salmonella, Shigella and Staphylococcus aureus were negative in two vomit and one stool samples from patients. Three specimens by Real-time PCR, and six by nested PCR were positive for norovirus among the three feces and three anal swabs samples. With the drinking water sterilization and health education, the epidemic had been controlled rapidly and effectively. CONCLUSION: The epidemic was a diarrhea outbreak that might be caused by norovirus through drinking the contaminated tap water A.

[Comparison between laparoscopic pyloromyotomy and open pyloromyotomy for infants with congenital hypertrophic pyloric stenosis]

OBJECTIVE: To compare the efficacy of laparoscopic pyloromyotomy with open pyloromyotomy in treatment of congenital hypertrophic pyloric stenosis(CHPS). METHODS: Fifteen patients (age 20%ape;90 days, body weight 2.5 approximate, equals 5.0 kg) with CHPS underwent laparoscopic pyloromyotomy (Group I) and 10 patients (age 26 approximate, equals 90 days, body weight 2.8 approximate, equals 4.5 kg) with CHPS underwent open pyloromyotomy (Group II). Ambulatory 24 hr esophageal pH metry and gastroesophageal mamometry were studied in two groups before and after surgery. RESULTS: All patients presented gastroesophageal reflux (GER) before operation and all reflux parameters were significantly decreased after operation (P<0.01). There was no significant difference between two groups in reflux parameters after surgery. Intragastric pressure (GP) significantly reduced in two groups after operation(3.83+/-1.45)mmHg compared with (2.38+/-0.54)mmHg P<0.01 in Group I,(4.52+/-1.96)mmHg compared with (2.38+/-0.72)mmHg P<0.05 in Guoup II). There was no significant difference in lower esophageal sphincter pressure (LESP), lower esophageal sphincter length (LESL) before and after operation in two groups. The mean operative time for Group I was (32+/-19) mins, which was close to that of Group II after an initial trail. Oral feeding was started 6 h postoperatively in Group I, which was earlier than that in Group II. No technical failures and complications in Group I were encountered. One wound infection and dehiscense was seen in Group II. CLUSION: Laparoscopic pyloromyotomy for infantile hypertrophic pyloric stenosis is safe and feasible, which has lesser complication and similar effect of antireflux as open pyloromyotomy.