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Acetogenic bacteria (acetogens) are a class of microorganisms with conserved Wood-Ljungdahl pathway that can utilize CO and CO 2 /H 2 as carbon source for autotrophic growth and convert these substrates to acetate and ethanol. Acetogens have great potential for the sustainable production of biofuels and bulk biochemicals using C1 gases (CO and CO 2 ) from industrial syngas and waste gases, which play an important role in achieving carbon neutrality. In recent years, with the development and improvement of gene editing methods, the metabolic engineering of acetogens is making rapid progress. With introduction of heterogeneous metabolic pathways, acetogens can improve the production capacity of native products or obtain the ability to synthesize non-native products. This paper reviews the recent application of metabolic engineering in acetogens. In addition, the challenges of metabolic engineering in acetogens are indicated, and strategies to address these challenges are also discussed., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Zhang, Li, Xi, Gao, Zhang, Liu, Li and Ma.)

Poor stability retards the industrialization of perovskite solar cells (PSCs). One of the effective ways to solve this issue is to modify the perovskite surface to improve the efficiency and stability of the PSCs. Herein, we synthesized CuFeS 2 nanocrystals and applied them to modify the perovskite surface. The efficiency of the PSCs with CuFeS 2 modification is improved to 20.17% from 18.64% for the control devices. Some investigations demonstrate that the CuFeS 2 modification passivates the perovskite surface defects and induces better energy band arrangement. Furthermore, the stability of the PSCs with CuFeS 2 modification is improved compared with the devices without CuFeS 2 modification. The efficiency of the PSCs with CuFeS 2 modification maintains 93% of its initial value, whereas that of the devices without CuFeS 2 modification decreases to 61% of the initial value. This work demonstrates that CuFeS 2 is a novel material used as a modification layer to enhance the efficiency and stability of the PSCs.

14 workers in the 1, 8-diaminonaphthalene workshop of a chemical company in Nantong City had symptoms or signs of varying degrees of pruritus and pigmentation of the face, neck and waist. Pathological examination of skin biopsies showed hyperkeratosis, the basal cells were liquefied and denatured. Seven workers were eventually diagnosed with occupational melanosis. To explore the causes of occupational melanosis caused by exposure to 1, 8-dinitronaphthalene and 1, 8-diaminonaphthalene, and to provide reference for the prevention and treatment of occupational melanosis in the future, this paper reported 14 cases of melanosis in the skin of workers in chemical industry.

In this paper, N-doped TiO 2 (N-TiO 2 ) nanorod arrays were synthesized with hydrothermal method, and perovskite solar cells were fabricated using them as electron transfer layer. The solar cell performance was optimized by changing the N doping contents. The power conversion efficiency of solar cells based on N-TiO 2 with the N doping content of 1% (N/Ti, atomic ratio) has been achieved 11.1%, which was 14.7% higher than that of solar cells based on un-doped TiO 2 . To get an insight into the improvement, some investigations were performed. The structure was examined with X-ray powder diffraction (XRD), and morphology was examined by scanning electron microscopy (SEM). Energy dispersive spectrometer (EDS) and Tauc plot spectra indicated the incorporation of N in TiO 2 nanorods. Absorption spectra showed higher absorption of visible light for N-TiO 2 than un-doped TiO 2 . The N doping reduced the energy band gap from 3.03 to 2.74 eV. The photoluminescence (PL) and time-resolved photoluminescence (TRPL) spectra displayed the faster electron transfer from perovskite layer to N-TiO 2 than to un-doped TiO 2 . Electrochemical impedance spectroscopy (EIS) showed the smaller resistance of device based on N-TiO 2 than that on un-doped TiO 2 .

Precursor solution of CH 3 NH 3 PbI 3-x Cl x for perovskite solar cells was conventionally prepared by mixing PbCl 2 and CH 3 NH 3 I with a mole ratio of 1:3 (PbCl 2 :CH 3 NH 3 I). While in the present study, CH 3 NH 3 PbI 3-x Cl x -based solar cells were fabricated using the precursor solutions containing PbCl 2 and CH 3 NH 3 I with the mole ratios of 1:3, 1.05:3, 1.1:3, and 1.15:3, respectively. The results display that the solar cells with the mole ratio of 1.1:3 present higher power conversion efficiency and less I-V hysteresis than those with the mole ratio of 1:3. Based on some investigations, it is concluded that the higher efficiency could be due to the smooth and pinhole free film formation, high optical absorption, suitable energy band gap, and the large electron transfer efficiency, and the less I-V hysteresis may be attributed to the small low frequency capacitance of the device.

Environmental pollution by emerging contaminants, e.g. pharmaceuticals, has become a matter of widespread concern in recent years. We investigated the membrane transport of diclofenac and its toxic effects on gene expression and the development of zebrafish embryos. The association of diclofenac with the embryos conformed to the general partition model at low concentration, the partition coefficient being 0.0033 ml per embryo. At high concentration, the interaction fitted the Freundlich model. Most of the diclofenac remained in the extracellular aqueous solution with less than 5% interacting with the embryo, about half of which was adsorbed on the membranes while the rest entered the cytoplasm. Concentrations of diclofenac over 10.13 μM were lethal to all the embryos, while 3.78 μM diclofenac was teratogenic. The development abnormalities at 4 day post treatment (dpt) include shorter body length, smaller eye, pericardial and body edema, lack of liver, intestine and circulation, muscle degeneration, and abnormal pigmentation. The portion of the diclofenac transferred into the embryo altered the expression of certain genes, e.g. down-regulation of Wnt3a and Gata4 and up-regulation of Wnt8a. The alteration of expression of such genes or the regulation of downstream genes could cause defects in the cardiovascular and nervous systems.

Objective: To investigate the diagnosis and treatment of pancreatic islet cell tumors., Methods: Fifty-one patients with islet cell tumors treated in our department from January 1991 to April 2011 were included in this study. The data of clinical features, diagnosis and treatment were retrospectively analyzed., Results: Among the 51 cases, 38 cases showed typical Whipple's triad, and the other 13 cases were non-functional islet cell tumors. In these 13 cases, 5 patients had no specific clinical symptoms, and 8 patients had abdominal distending pain. The positive rates of imaging were: B-ultrasound 43.1%, multi-slice spiral CT 69.8%; MRI 62.5%, endoscopic ultrasonography (EUS) 64.7% (11/17), and intraoperative ultrasound (IOUS) 96.3%, the differences among them were statistically significant (P<0.05). All patients underwent surgical treatment. Postoperative pancreatic leakage happened in 6 cases. Finally all the patients recovered after effective external drainage, anti-infection treatment and nutritional support., Conclusions: Intraoperative ultrasonography (IOUS) has a higher accuracy in the diagnosis of pancreatic islet cell tumors, compared with preoperative B-ultrasonography, CT, MRI, and endoscopic ultrasound (EUS). The most effective treatment of this disease is surgery.

In the title complex, [Zn(2)(C(8)H(3)NO(6))(2)(CH(4)N(2)S)(4)]·2H(2)O, the carboxyl-ate groups of the 3-nitro-phthalate ligands coordinate in a bis-monodentate mode to the Zn(II) cations. This results in the formation of a centrosymmetric dimer containing two Zn(II) cations with distorted tetra-hedral geometries provided by the O atoms of two different 3-nitro-phthalate dianions and the S atoms of two non-equivalent coordinated thio-urea mol-ecules. The crystal structure exhibits N-H⋯O and O-H⋯O hydrogen bonds which link the dimers into a three-dimensional network.

The objective of this study was to investigate the change of native immune adhering function (ENIAF) in self-plasma of patients with hematologic and lymphoid neoplasms and its effect on the killing activity of NK cells. The whole blood was anticoagulated with citric acid. 5 microl precipitated red blood cells and 500 microl plasma of patients or controls were directly mixed with 750 microl quantitative K562 cells at 37 degrees C for 30 minutes. One K562 cell attached by one or more erythrocytes was counted as one rosette, the ratio of rosettes was calculated. Using K562 cells as target cells, the killing activity of NK cells isolated from normal persons was detected by MTT assay, the change of the killing activity was observed after adding RBCs. The results indicated that the ratio of rosettes formed by RBCs of 21 normal controls and K562 cells was 15.3% +/- 6.4%, and the ratio of rosettes formed by RBCs of 24 patients and K562 cells was 7.6% +/- 7.0%. The ability of ENIAF in patients with hematologic and lymphoid neoplasms was significantly lower than that in healthy individuals (t = 3.61, p < 0.001). The killing rate of NK cells in peripheral blood of normal individuals was 67% - 71% without adding RBCs, and it increased by 14.7% +/- 5.2% after adding RBCs of normal controls but decreased by 4.3% +/- 7.6% with RBCs of patients. It is concluded that the ENIAF of RBCs in patients with hematopoietic and lymphoid neoplasms decreases, accompanying the reduction of the killing activity of NK cells to K562 cells, so to detect change of ENIAF may be helpful for the assessment of the immunological function of patients with hematopoietic and lymphoid neoplasms.