Engineering a solar formic acid/pentose (SFAP) pathway in Escherichia coli for lactic acid production.

Microbial CO2 fixation into lactic acid (LA) is an important approach for low-carbon biomanufacturing. Engineering microbes to utilize CO2 and sugar as co-substrates can create efficient pathways through input of moderate reducing power to drive CO2 fixation into product. However, to achieve complete conservation of organic carbon, how to engineer the CO2-fixing modules compatible with native central metabolism and merge the processes for improving bioproduction of LA is a big challenge. In this study, we designed and constructed a solar formic acid/pentose (SFAP) pathway in Escherichia coli, which enabled CO2 fixation merging into sugar catabolism to produce LA. In the SFAP pathway, adequate reducing equivalents from formate oxidation drive glucose metabolism shifting from glycolysis to the pentose phosphate pathway. The Rubisco-based CO2 fixation and sequential reduction of C3 intermediates are conducted to produce LA stoichiometrically. CO2 fixation theoretically can bring a 20% increase of LA production compared with sole glucose feedstock. This SFAP pathway in the integration of photoelectrochemical cell and an engineered Escherichia coli opens an efficient way for fixing CO2 into value-added bioproducts.

The association between low serum calcium level and new-onset atrial fibrillation after coronary artery bypass grafting.

OBJECTIVES: This study aims to investigate the relationship between serum calcium (SC) levels and the incidence of postoperative atrial fibrillation (POAF) in patients undergoing coronary artery bypass graft surgery. METHODS: This retrospective, observational cohort study consecutively enrolled patients undergoing isolated coronary artery bypass grafting in Beijing Anzhen Hospital from January 2018 to December 2021. Patients with a previous history of atrial fibrillation or atrial flutter or requiring concomitant cardiac surgery were excluded. A logistic regression model was used to determine predictors of POAF. Multivariable adjustment, inverse probability of treatment weighting and propensity score matching were used to adjust for confounders. Moreover, we conducted univariable and multivariable logistic regression analyses on preoperative and postoperative SC and ionized SC levels. RESULTS: The analysis encompassed 12 293 patients. The POAF rate was significantly higher in patients with low SC level than those without (1379 [33.9%] vs 2375 [28.9%], P < 0.001). Low SC level was associated with an increased odds ratio of POAF (odds ratio [95% confidence interval]: 1.27 [1.18-1.37], P < 0.001). Inverse probability of treatment weighting and propensity score matching analyses confirmed the results. The increased POAF rate in low SC level group still existed among subgroup analysis based on different age, sex, body mass index, hypertension, hyperlipidaemia, CHA2DS2-VASc and magnesium. CONCLUSIONS: Low SC level indicates elevated POAF risk in patients undergoing isolated coronary artery bypass graft surgery even after the adjustment for age, sex, cardiovascular risk factors, echocardiographic parameters and laboratory markers.

Double-layer horizontal cross sutures for intra-atrial mitral valve implantation: An effective surgical method for severe mitral annular calcification.

Objective: Severe mitral annular calcification (MAC) can make prosthetic implantation extremely difficult. Although intra-atrial mitral valve prosthesis implantation without annular decalcification offers a simpler approach, it poses a potential rupture risk due to high left ventricular pressure. We developed a double-layer (DL) horizontal cross-suture technique, which ensures close proximity of the valve prosthesis to the calcified annulus and segregates the left atrial wall from the left ventricle. The aim of this study was to compare the outcomes of DL suture with conventional single-layer (SL) suture in patients with severe MAC. Methods: This retrospective cohort study consecutively enrolled patients with severe MAC undergoing mitral valve replacement at Beijing Anzhen Hospital from May 2018 to December 2022. A detailed description of the DL suture method is described. Follow-up medical evaluations, including transthoracic echocardiography measurements, were obtained through outpatient chart reviews. Results: The study included 10 patients in the DL suture group and 20 in the SL suture group. All patients in the DL group and all but 3 in the SL group achieved technical success. Compared with the SL group, the DL suture technique was associated with lower rates of perivalvular leakage, stroke, new-onset atrial fibrillation, reoperation, and 30-day mortality. Follow-up was complete, with 1 late mortality in the DL group due to stroke and 4 cardiovascular deaths in the SL group. Conclusions: The DL horizontal cross-suture technique offers a more effective and safer approach for intra-atrial mitral valve implantation in severe MAC cases than the conventional SL suture method.

Surface energy partitioning and evapotranspiration in a Pinus tabuliformis plantation in Northeast China.

Examining the land-atmosphere interaction in vegetation rehabilitation areas is important for better understanding of land surface processes affected by human activities. In this study, energy flux observations were used to investigate surface energy partitioning and evapotranspiration (ET) in a Pinus tabuliformis plantation in Northeast China in 2020 and 2021. The sensible heat flux (H) was the dominant component of Rn, and the ratio of H to the latent heat flux was higher than 1 at all growth stages. The two most important factors influencing the midday evaporative fraction and daily ET were the normalized difference vegetation index (NDVI) and soil water content at 10 cm depth (SWC10). Cumulative precipitation (P) minus ET was 62.83 and 239.90 mm in 2020 (annual P of 435.2 mm) and 2021 (annual P of 632.8 mm), respectively. The midday Priestley-Taylor coefficient (α), surface conductance (gs), and decoupling coefficient increased gradually from the onset of the mid-growing stage and decreased from the later growing stage. Midday α and gs increased with NDVI and SWC10 increasing until the NDVI (0.5) and SWC10 (0.17 mm3 mm-3) thresholds were reached, respectively. Midday α and gs were significantly influenced by vapor pressure deficit below 3 kPa, and the threshold value of midday gs was approximately 12 mm s-1. In conclusion, this Pinus tabuliformis plantation regulated surface energy partitioning properly, and left a part of P for surface runoff and groundwater recharge in the semiarid region of Northeast China.

Single-cell mapping reveals dysregulation of immune cell populations and VISTA+ monocytes in myasthenia gravis.

The pathogenesis and progression of myasthenia gravis (MG), an autoimmune disease, involve abnormal function and composition of several immune cell populations. However, details of this dysregulation remain unclear. We performed a cross-section analysis using cytometry time-of-flight on blood samples from 12 generalized MG without glucocorticoid or other immunosuppressant treatment, and 10 sex- and age-matched healthy controls. Combining data from an external validation cohort (MG n = 38, control n = 21), bulk-RNA sequencing and single-cell RNA sequencing, alterations in immune cell populations and differential expression of immune check point were revealed. Several switched memory B cell subsets (CD3- CD19+ CD27+ IgD- CD38+/-) were increased in MG patients. The number of HLA- DQ- CD38+ naïve B cells was higher in MG patients and correlated with the quantitative MG score (QMG). Among NK cells, the number of CD56+ CD16+ NK cells and CD56+ CD16+ CD8+ NK cells were decreased in MG patients and positively correlated with QMG. VISTA+ monocytes were increased in MG patients. Classical T cell subsets showed no significant change; however, the expression of VISTA, LAG3, CTLA4, and CXCR5 was higher in T cells from MG patients. The expression of CD38 was higher in neutrophils from MG patients. The external validation cohort validated the dysregulation of NK cell subtypes, and differences were also observed in subgroups of patients. Bulk-RNA sequencing also revealed increased mRNA expression of VSIR in monocytes of MG patients compared to those from healthy controls, and the antigen presentation and processing pathway was identified as enriched in the functional characterization of VISTA+ monocytes via single-cell RNA sequencing. Our study revealed alterations in several immune cell subsets and identified potential cellular biomarkers for MG diagnosis and disease severity assessment. In addition, the abnormal expression of multiple immune checkpoints in MG provides further rationale for the investigation of immune-checkpoint-related therapy.

Recent advances in separation applications of polymerized high internal phase emulsions.

Polymerized high internal phase emulsions as highly porous adsorption materials have received increasing attention and wide applications in separation science in recent years due to their remarkable merits such as highly interconnected porosity, high permeability, good thermal and chemical stability, and tailorable chemistry. In this review, we attempt to introduce some strategies to utilize polymerized high internal phase emulsions for separation science, and highlight the recent advances made in the applications of polymerized high internal phase emulsions for diverse separation of small organic molecules, carbon dioxide, metal ions, proteins, and other interesting targets. Potential challenges and future perspectives for polymerized high internal phase emulsion research in the field of separation science are also speculated at the end of this review.

Quantifying aircraft emissions of Shanghai Pudong International Airport with aircraft ground operational data.

The air traffic growth at Shanghai Pudong International Airport (PVG) has attracted much concern over the potential impacts on local air quality and human health; however, the emission contributions due to aircraft activities, impact on air quality and health effects remain unclear. In this study, the ground operational data derived from the Aircraft Communication Addressing and Reporting System (ACARS) dataset are newly utilized to obtain the PVG-specific emission parameters of 10 distinct aircraft-engine combinations during the taxi-in and taxi-out phases of the landing and take-off (LTO) cycle. The resulting emission parameters, together with PVG-specific operational conditions, are applied to quantify the annual emissions in 2017 for main engines and auxiliary power units (APUs) at PVG, emission variations caused by mixing layer height, sensitivity of black carbon (BC) emissions to the estimation method and sensitivity of PM2.5 emissions to the fuel sulfur content (FSC). The results show noticeable discrepancies between the corrected fuel flows and NOx emission indices (EIs) and those certified by the International Civil Aviation Organization (ICAO). The annual emissions of hydrocarbons (HC), CO, NOx, NO, NO2, HONO, HNO3, NOy, SO2, SO42-, BC, organic carbon (OC) and PM2.5 with corrected emission parameters are 3.82 × 105 kg, 4.35 × 106 kg, 5.36 × 106 kg, 4.40 × 106 kg, 9.58 × 105 kg, 1.03 × 105 kg, 3.83 × 103 kg, 5.47 × 106 kg, 3.56 × 105 kg, 1.31 × 104 kg, 5.43 × 104 kg, 4.73 × 103 kg and 7.22 × 104 kg, respectively, while the application of the maximum height of the mixing layer contributes to emission increases as high as 16.9% (NOx). An alternative estimation of BC emissions leads to an increase of 50% compared with first-order approximation 3 (FOA3), while a reduction in PM2.5 emissions can be expected by minimizing the FSC.

Controllable Surface Reorganization Engineering on Cobalt Phosphide Nanowire Arrays for Efficient Alkaline Hydrogen Evolution Reaction.

Developing highly efficient hydrogen evolution reaction (HER) catalysts in alkaline media is considered significant and valuable for water splitting. Herein, it is demonstrated that surface reorganization engineering by oxygen plasma engraving on electocatalysts successfully realizes a dramatically enhanced alkaline HER activity. Taking CoP nanowire arrays grown on carbon cloth (denoted as CoP NWs/CC) as an example, the oxygen plasma engraving can trigger moderate CoOx species formation on the surface of the CoP NWs/CC, which is visually verified by the X-ray absorption fine structure, high-resolution transmission electron microscopy, and energy-dispersive spectrometer (EDS) mapping. Benefiting from the moderate CoOx species formed on the surface, which can promote the water dissociation in alkaline HER, the surface reorganization of the CoP NWs/CC realizes almost fourfold enhanced alkaline HER activity and a 180 mV decreased overpotential at 100 mA cm-2 , compared with the pristine ones. More interestingly, this surface reorganization strategy by oxygen plasma engraving can also be effective to other electrocatalysts such as free-standing CoP, Co4 N, O-CoSe2 , and C-CoSe2 nanowires, which verifies the universality of the strategy. This work thus opens up new avenues for designing alkaline HER electrocatalysts based on oxygen plasma engraving.

Promoting Active Species Generation by Electrochemical Activation in Alkaline Media for Efficient Electrocatalytic Oxygen Evolution in Neutral Media.

In this study, by using dicobalt phosphide nanoparticles as precatalysts, we demonstrated that electrochemical activation of metallic precatalysts in alkaline media (comparing with directly electrochemical activation in neutral media) could significantly promote the OER catalysis in neutral media, specifically realizing a 2-fold enhanced activity and meanwhile showing a greatly decreased overpotential of about 100 mV at 10 mA cm-2. Compared directly with electrochemical activation in neutral media, the electrochemical activation in harsh alkaline media could easily break the strong Co-Co bond and promote active species generation on the surface of metallic Co2P, thus accounting for the enhancement of neutral OER activity, which is also evidenced by HRTEM and the electrochemical double-layer capacitance measurement. The activation of electrochemical oxidation of metallic precatalysts in alkaline media enhanced neutral OER catalysis could also be observed on CoP nanoparticles and Ni2P nanoparticles, suggesting this is a generic strategy. Our work highlights that the activation of electrochemical oxidation of metallic precatalysts in alkaline media would pave new avenues for the design of advanced neutral OER electrocatalysts.

[Correction of whistle deformity in bilateral cleft lip with lower lip bipedicle orbicularis oris musculomucosal island flap].

Objective: To explore a new method to correct the whistle deformity in bilateral cleft lip. Methods: A lower lip bipedicle orbicularis oris musculomucosal island flap was designed to repair the upper vermilion defect.The pedicle of this flap was deepidermidalized and then embedded into the upper lip. The dry lip in the central was reserved to reconstruct the vermilion tubercle. Results: From Aug.2013 to Aug.2015,10 cases were treated successfully with primary healing. With the follow-up period of 5-17 months, the appearance of upper lip was greatly improved with a balanced proportion and full lip tubercle. Conclusions: This lower lip bipedicle orbicularis oris musculomucosal island flap is an ideal method for the correction of whistle deformity in bilateral cleft lip.

Adipocyte regeneration after free fat transplantation: promotion by stromal vascular fraction cells.

Our objective was to explore the mechanism of cell-assisted adipose transplantation by using freshly isolated human stromal vascular fraction (SVF) cells and to observe the dynamic changes of the graft after transplantation. The SVF was isolated from human liposuction aspirates, and 0.5 ml adipose tissue was mixed with 1 × 10(6) SVF cells or culture medium then injected to nude mice subcutaneously. At 1, 4, 7, 14, 30, 60, and 90 days after transplantation, samples were harvested for 1) general observation and retention rate; 2) whole-mount stain; 3) H&E stain; 4) immunohistochemical staining for S100, CD68, and CD34; 5) ELISA for VEGF and bFGF; 6) peroxisome proliferator-activated receptor-γ (PPARγ) fluorescence in situ hybridization. The retention rate in the experiment group was markedly higher than that in the control group. Whole-mount stain shows most of the cells in the center of the graft could not survive the ischemia until day 14. Histology showed new vessels on the surface of the graft at 3 days. However, in the control group, fewer newly formed vessels were detected until day 7. In the late stage of transplantation, gradual fibrosis was found in the graft, and the tissue was divided into a grid-like structure. A large number of round neonatal adipocytes with big nuclei in the center were found surrounding the new vessels, which were S100 and CD34 positive and CD68 negative. In the late stage of transplantation, most of the neonatal adipocytes were human PPARγ positive. Moreover, the SVF group showed a higher level of VEGF and bFGF. SVF assisting adipose transplantation could increase the retention rate of the graft through promoting adipose tissue regeneration via secretion of growth factors, promotion of angiogenesis, and increasing the density of mesenchymal stem cells.

[Reverse effect of Yinchenhao decoction in dimethyl nitrosamine-induced hepatic fibrosis in rats].

OBJECTIVE: To discuss the reverse effect of Yinchenhao decoction(YCHD) in dimethyl nitrosamine (DMN)-induced hepatic fibrosis in rats. METHOD: The rat hepatic fibrosis model was established through the intraperitoneal injection with 1% dimethyl nitrosamine (DMN) with a dose of 1.0 mL x kg(-1) x d(-1) for consecutively three weeks, once for the first three days of each. The rats were randomly divided into six groups: the silymarin positive control group (50.0 mg x kg(-1) x d(-1), YCHD high (20.0 g x kg(-1) d(-1)), middle (8.0 g x kg(-1) x d(-1)) and low (3.2 g x kg(-1) x d(-1)) dose groups, the model group and the normal control group. The model group and the normal control group were orally administered with normal saline for consecutively five weeks. The pathologic changes in liver tissues were observed by HE staining. The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), g-glutamyltransferase (g-GGT), hyaluronic acid (HA), laminin (LN), collagen type IV (CIV) and type III procollagen amino terminal peptide (PIIINP) in serum were determined. The metabolite profiling of amino acid and the content of hydroxyproline in liver tissues were also measured. RESULT: Compared with the model group, YCHD high and middle dose groups could significantly reverse the pathologic changes in liver tissues of rats. YCHD could reduce the levels of ALT, AST, gamma-GGT, HA, LN, CIV, PIIINP in serum and the content of hydroxyproline in liver tissues in a dose-dependent manner, and altered the metabolite profiling of amino acid in rat liver tissues. CONCLUSION: YCHD has the effect in reversing dimethyl nitrosamine induced hepatic fibrosis in rats.

Quantitative volumetric analysis of progressive hemifacial atrophy corrected using stromal vascular fraction-supplemented autologous fat grafts.

BACKGROUND: Progressive hemifacial atrophy (Parry-Romberg disease) is rare and involves all skin layers and subcutaneous soft and hard tissue. Autologous fat grafting has revolutionized the field of soft-tissue reconstruction and augmentation, but long-term maintenance is unpredictable. Stromal vascular fraction (SVF)-supplemented cell therapy offers new hope for improving fat graft survival, with good long-term results, but efficacy and long-term outcome in the clinic are rarely studied using objective data. OBJECTIVE: To compare the long-term viability of SVF-supplemented fat grafts and fat grafts alone for contour reconstruction of progressive hemifacial atrophy using quantitative volume analysis. METHODS: We treated 20 patients with stable hemifacial atrophy for at least 2 years with SVF-supplemented autologous fat grafting (n = 10) or fat grafting alone (n = 10). All patients were followed up every 3 months. Hemifacial volume was measured using computed tomography and the Philips Extended Brilliance Workspace. RESULTS: All patients had successful outcomes without complications, but fat survival and clinical improvement was greater with SVF-supplemented grafting than fat grafting alone after 6 months. CONCLUSION: SVF-supplemented autologous fat transplantation is effective and safe for treating progressive hemifacial atrophy and can enhance the survival of grafts in the face without major complications.

Hypoxia preconditioned human adipose derived mesenchymal stem cells enhance angiogenic potential via secretion of increased VEGF and bFGF.

Mesenchymal stem cells (MSCs) are adult multipotent cells found in bone marrow, adipose tissue, and other adult tissues. MSCs improve regeneration of injured tissues in vivo, but the mechanisms remain unclear. Typically, MSCs are cultured under ambient or normoxic conditions (21% O2 ). However, the physiological niches of MSCs have much lower oxygen tension. When used as a therapeutic tool to repair tissue injuries, MSCs cultured in standard conditions must adapt from 21% O2 in culture to <1% O2 in ischemic tissue. We have examined the effects of hypoxia preconditioning (1% O2 ) in human adipose derived mesenchymal stem cells (AD-MSCs) to discover the conditions that best enhance their tissue regenerative potential. We demonstrate that AD-MSCs respond positively to hypoxia compared with normoxia preconditioning, show decreased apoptosis even in severe microenvironmental conditions (such as a low-serum medium), and an increased expression of the angiogenic factors, vascular endothelial growth factor and basic fibroblast growth factor. Human umbilical vein endothelial cells have higher vitality and lower apoptosis when cultured in medium taken from hypoxia-preconditioned AD-MSCs, as well as significantly increased capillary-like structures with this medium on Matrigel. The data suggest that hypoxia preconditioned AD-MSCs can improve tissue regeneration.

Stromal vascular fraction (SVF) cells enhance long-term survival of autologous fat grafting through the facilitation of M2 macrophages.

Optimum perfusion may be the key to the endurance, and hence survival, of autologous adipose tissue transportation. Stromal vascular fraction (SVF) cell therapy can greatly improve the survival of fat grafts by enhancing angiogenesis. However, SVF cells are poorly retained in later stages of SVF-assisted adipose tissue transplant. Therefore, it hardly defines the angiogenic effect through long-term transportation. Adipose tissue suffers from acute hypoxia in the early stage of transportation, leading to the recruitment of macrophages. M2 macrophages enhance angiogenesis in adipose transplantation by acting as an angiogenic signal source, promoting tip cell migration and assisting tip cell fusion. Furthermore, the angiogenic and anti-inflammatory micro-environment in the graft created by M2 macrophages may stimulate the transformation of infiltrating macrophages to M2 macrophages. These M2 macrophages may enhance the long-term retention of graft through angiogenesis. Based on these observations, we postulate that the long-term angiogenic effect of SVF cells may be achieved through the facilitation of the M2 macrophages.

Role of adipose-derived stem cells in enhancing angiogenesis early after aspirated fat transplantation: induction or differentiation?

Autologous fat tissue has been used as a potential filler for soft-tissue defects, despite unpredictable clinical outcomes and low graft survival. Co-transplantation of adipose-derived stem cells (ASCs) is an alternative therapeutic approach to effectively enhance the survival and quality of transplanted fat tissue by increasing neovascularization. Nevertheless, the mechanisms by which ASCs exerted their angiogenic effects remain obscure. ASCs can secrete several angiogenic growth factors, for example vascular endothelial growth factor, hepatocyte growth factor and basic fibroblast growth factor. Hypoxic conditions may promote the proliferation of ASCs and their secretion. However, the differentiation of ASCs into endothelial cells (ECs), pericytes and smooth muscular cells in vivo has not been confirmed. The role of ASCs early after aspirated fat transplantation may be to induce new vessels from the recipient region to grow around and into the graft by releasing significant amounts of angiogenic growth factors rather than to differentiate into ECs, pericytes or smooth muscular cells forming new vessels, an effect that might be enhanced by hypoxia.

Sustained release of naproxen in a new kind delivery system of carbon nanotubes hydrogel.

In this paper, carbon nanotubes (CNTs) were added into chitosan (CS) hydrogels in the form of chitosan modified CNTs (CS-CNTs) composites to prepare carbon nanotubes hydrogels (CNTs-GEL). The products, named CS-MWCNTs, were characterized by scanning electron microscope (SEM) and Fourier transform infrared (FTIR) spectroscopy. Swelling properties and effect of pH on controlled release performance of the two kinds of hydrogels, CNTs- GEL and pure chitosan hydrogels without CNTs (GEL), were investigated respectively. The results showed that CNTs-GEL possess better controlled release performance than GEL. The releasing equilibrium time of CNTs-GEL was longer than that of GEL in both pH = w7.4 and pH=1.2 conditions, although the release ratios of the model drug are similar in the same pH buffer solutions. It is found that release kinetics is better fitted Ritger-Peppas empirical model indicating a fick-diffusion process in pH = 1.2, while in pH = 7.4 it was non-fick diffusion involving surface diffusion and corrosion diffusion processes.