GSK3 phosphorylates and regulates the Green Revolution protein Rht-B1b to reduce plant height in wheat.

The utilization of stabilized DELLA proteins Rht-B1b and Rht-D1b was crucial for increasing wheat (Triticum aestivum) productivity during the Green Revolution. However, the underlying mechanisms remain to be clarified. Here, we cloned a gain-of-function allele of the GSK3/SHAGGY-like kinase-encoding gene GSK3 by characterizing a dwarf wheat mutant. Furthermore, we determined that GSK3 interacts with and phosphorylates the Green Revolution protein Rht-B1b to promote it to reduce plant height in wheat. Specifically, phosphorylation by GSK3 may enhance the activity and stability of Rht-B1b, allowing it to inhibit the activities of its target transcription factors. Taken together, we reveal a positive regulatory mechanism for the Green Revolution protein Rht-B1b by GSK3, which might have contributed to the Green Revolution in wheat.

Predicting the effects of mutations on protein solubility using graph convolution network and protein language model representation.

Solubility is one of the most important properties of protein. Protein solubility can be greatly changed by single amino acid mutations and the reduced protein solubility could lead to diseases. Since experimental methods to determine solubility are time-consuming and expensive, in-silico methods have been developed to predict the protein solubility changes caused by mutations mostly through protein evolution information. However, these methods are slow since it takes long time to obtain evolution information through multiple sequence alignment. In addition, these methods are of low performance because they do not fully utilize protein 3D structures due to a lack of experimental structures for most proteins. Here, we proposed a sequence-based method DeepMutSol to predict solubility change from residual mutations based on the Graph Convolutional Neural Network (GCN), where the protein graph was initiated according to predicted protein structure from Alphafold2, and the nodes (residues) were represented by protein language embeddings. To circumvent the small data of solubility changes, we further pretrained the model over absolute protein solubility. DeepMutSol was shown to outperform state-of-the-art methods in benchmark tests. In addition, we applied the method to clinically relevant genes from the ClinVar database and the predicted solubility changes were shown able to separate pathogenic mutations. All of the data sets and the source code are available at https://github.com/biomed-AI/DeepMutSol.

Identification and functional analysis of a chromosome 2D fragment harboring TaFPF1 gene with the potential for yield improvement using a late heading wheat mutant.

KEY MESSAGE: A chromosome fragment influencing wheat heading and grain size was identified using mapping of m406 mutant. The study of TaFPF1 in this fragment provides more insights into wheat yield improvement. In recent years, wheat production has faced formidable challenges driven by rapid population growth and climate change, emphasizing the importance of improving specific agronomic traits such as heading date, spike length, and grain size. To identify potential genes for improving these traits, we screened a wheat EMS mutant library and identified a mutant, designated m406, which exhibited a significantly delayed heading date compared to the wild-type. Intriguingly, the mutant also displayed significantly longer spike and larger grain size. Genetic analysis revealed that a single recessive gene was responsible for the delayed heading. Surprisingly, a large 46.58 Mb deletion at the terminal region of chromosome arm 2DS in the mutant was identified through fine mapping and fluorescence in situ hybridization. Thus, the phenotypes of the mutant m406 are controlled by a group of linked genes. This deletion encompassed 917 annotated high-confidence genes, including the previously studied wheat genes Ppd1 and TaDA1, which could affect heading date and grain size. Multiple genes in this region probably contribute to the phenotypes of m406. We further investigated the function of TaFPF1 using gene editing. TaFPF1 knockout mutants showed delayed heading and increased grain size. Moreover, we identified the direct upstream gene of TaFPF1 and investigated its relationship with other important flowering genes. Our study not only identified more genes affecting heading and grain development within this deleted region but also highlighted the potential of combining these genes for improvement of wheat traits.

TaMYB72 directly activates the expression of TaFT to promote heading and enhance grain yield traits in wheat (Triticum aestivum L.).

Heading date, grain number per spike, and grain weight are crucial traits affecting yield and adaptability in wheat. The transcription factor TaMYB72 is an important regulator of wheat grain yield and its knock-out mutants can be used as germplasm resources for wheat improvement.

Extracellular matrix-regulator MMPA is required for the orderly proliferation of neoblasts and differentiation of ectodermal progenitor cells in the planarian Dugesia japonica.

Matrix metalloproteinases (MMPs) are members of a family of zinc-dependent metallopeptidase proteins that are widely found in plants, animals, and microorganisms. As the regulators of the extracellular matrix and basement membrane, MMPs play an important role in embryogenesis, development, innate immunity, and regeneration. However, the function of MMP family in planarian, a model for regeneration research, is still ambiguous. Here, we cloned 5 MMPs genes from Dugesia japonica and found that DjMMPA was associated with the process of regeneration, neoblasts cell maintenance confusion and destruction. Loss of DjMMPA led to homeostasis confusion and eventually death, owing to neoblasts proliferation disorder. Additionally, DjMMPA RNAi-treated animals had impaired regeneration after amputation. Furthermore, knockdown of DjMMPA had noticeable defects in cell differentiation of ectoderm, especially in eyes and neural progenitor cells, possibly by inhibiting Wnt signaling. Our results suggest that extracellular matrix-regulator MMPA is required for the orderly proliferation of neoblasts and differentiation of ectodermal progenitor cells in the planarian, which provide valuable information for further explorations into the molecular mechanism of MMPS, stem cells, and regeneration.

Identification of the early leaf senescence gene ELS3 in bread wheat (Triticum aestivum L.).

MAIN CONCLUSION: Characterization of the early leaf senescence mutant els3 and identification of its causal gene ELS3, which encodes an LRR-RLK protein in wheat. Leaf senescence is an important agronomic trait that affects both crop yield and quality. However, few senescence-related genes in wheat have been cloned and functionally analyzed. Here, we report the characterization of the early leaf senescence mutant els3 and fine mapping of its causal gene ELS3 in wheat. Compared with wild-type Yanzhan4110 (YZ4110), the els3 mutant had a decreased chlorophyll content and a degraded chloroplast structure after the flowering stage. Further biochemical assays in flag leaves showed that the superoxide anion and hydrogen peroxide contents increased, while the activities of antioxidant enzymes, including catalase, superoxide dismutase and glutathione reductase, decreased gradually after the flowering stage in the els3 mutant. To clone the causal gene underlying the phenotype of leaf senescence, a genetic map was constructed using 10,133 individuals of F2:3 populations, and ELS3 was located in a 2.52 Mb region on chromosome 2DL containing 16 putative genes. Subsequent sequence analysis and gene annotation identified only one SNP (C to T) in the first exon of TraesCS2D02G332700, resulting in an amino acid substitution (Pro329Ser), and TraesCS2D02G332700 was preliminarily considered as the candidate gene of ELS3. ELS3 encodes a leucine-rich repeat receptor-like kinase (LRR-RLK) protein that is localized on the cell membrane. We also found that the transient expression of mutant TraesCS2D02G332700 can induce leaf senescence in N. benthamiana. Taken together, TraesCS2D02G332700 is likely to be the candidate gene of ELS3 and may have a function in regulating leaf senescence.

A Glu209Lys substitution in DRG1/TaACT7, which disturbs F-actin organization, reduces plant height and grain length in bread wheat.

Plant height and grain size are two important agronomic traits that are closely related to crop yield. Numerous dwarf and grain-shape mutants have been studied to identify genes that can be used to increase crop yield and improve breeding programs. In this study, we characterized a dominant mutant, dwarf and round grain 1 (drg1-D), in bread wheat (Triticum aestivum L.). drg1-D plants exhibit multiple phenotypic changes, including dwarfism, round grains, and insensitivity to brassinosteroids (BR). Cell structure observation in drg1-D mutant plants showed that the reduced organ size is due to irregular cell shape. Using map-based cloning and verification in transgenic plants, we found that a Glu209Lys substitution in the DRG1 protein is responsible for the irregular cell size and arrangement in the drg1-D mutant. DRG1/TaACT7 encodes an actin family protein that is essential for polymerization stability and microfilament (MF) formation. In addition, the BR response and vesicular transport were altered by the abnormal actin cytoskeleton in drg1-D mutant plants. Our study demonstrates that DRG1/TaACT7 plays an important role in wheat cell shape determination by modulating actin organization and intracellular material transport, which could in the longer term provide tools to better understand the polymerization of actin and its assembly into filaments and arrays.

Retrospective analysis of the endometrial preparation protocols for frozen-thawed embryo transfer cycles in women with endometriosis.

BACKGROUND: There was inconsistency in optimal endometrial preparation protocol for frozen-thawed embryo transfer (FET) in patients with endometriosis. We conducted this study to investigate the effect of different endometrial preparation protocols on the pregnancy outcomes in patients with endometriosis undergoing FET cycles, and determine the optimal number of GnRHa injections in GnRHa-HRT protocols. METHOD(S): This was a retrospective cohort analysis of women with endometriosis who underwent FET cycles at a single university-based center. This study retrospectively analyzed 2048 FET cycles in our center from 2011 to 2020. According to the endometrial preparation protocols, patients were divided into 4 groups: gonadotropin releasing hormone agonist-hormone replacement therapy(GnRHa-HRT), hormone replacement therapy(HRT), ovulation induction(OI), and natural cycle(NC). In the GnRHa-HRT group, patients were further divided into 3 groups: one injection of GnRHa, two injections of GnRHa, and three or more injections of GnRHa. The primary outcome was the clinical pregnancy rate. Propensity score matching was used to adjust for potential non-similarities among the groups. Multivariate logistic regression analysis was performed to figure out the risk factors for pregnancy outcomes. RESULT(S): There were no statistical differences in pregnancy outcomes among the four endometrial preparation protocols in FET cycles with endometriosis patients, the results retained after propensity score matching(PSM). And in endometriosis patients complicated with adenomyosis, the results remained similar. In patients with GnRHa-HRT protocol, there were no differences in clinical pregnancy rate and live birth rate with different numbers of GnRHa injections, the early miscarriage rate were 18% in the two injections of GnRHa group and 6.5% in the one injection of GnRHa group(P = 0.017). Multifactorial logistic regression analysis showed that two injections of GnRHa before FET was associated with increased early miscarriage rate compared with one injection of GnRHa[adjusted OR (95% CI): 3.116(1.079-8.998),p = 0.036]. CONCLUSION(S): The four kinds of endometrial preparation protocols for FET, GnRHa-HRT, HRT, OI and NC had similar pregnancy outcomes in patients with endometriosis. In endometriosis patients complicated with adenomyosis, the results remained similar. In patients with endometriosis undergoing GnRHa-HRT protocol for FET, more injections of GnRHa had no more advantages in pregnancy outcomes, on the contrary, it might increase the early miscarriage rate.

GSK3 regulates VRN1 to control flowering time in wheat.

GLYCOGEN SYNTHASE KINASE 3 physically interacts with VRN1 and regulates its accumulation to mediate flowering in wheat.

Subfertile Chinese patients with diminished ovarian reserve: An analysis of pregnancy outcomes of ART cycles.

Objective: To analyze the pregnancy outcomes of patients presenting with infertility solely due to diminished ovarian reserve (DOR) and treated by assisted reproductive technology (ART), including artificial insemination by husband (AIH) and in vitro fertilization (IVF). Methods: This was a retrospective study of subfertile patients due to DOR attending the Center for Reproductive Medicine in Guangzhou, China, between January 2010 and October 2015. Patients were assigned into either the AIH or IVF group. Within each group, these patients were further subgrouped based on their serum basal follicle-stimulating hormone (bFSH) level (10 ≤ bFSH ≤ 12IU/L and bFSH > 12IU/L) and age (20-30, 31-35, 36-40, and 41-45 years). The live birth rates were compared among these groups and subgroups. Result: A total of 1,003 patients with a median age of 38.91 (21-45) years were enrolled in the study. The live birth rate following AIH was 5.61% (25/446), which was significantly lower than that following IVF (25.13%; 140/557). In the subgroup analysis, the cumulative live birth rates in AIH group were significantly lower than those in the IVF groups (in the 10-12 IU/L bFSH subgroup, 13.74% vs. 41.13% (P<0.05) for patients aged ≤35 years, and 4.82% vs. 19.77% (P<0.05) for patients aged >35 years; in the >12 IU/L bFSH subgroup, 9.52% vs. 29.91% (P<0.05) for patients aged ≤35 years, and 5.71% vs. 20.55% (P<0.05) for patients aged >35 years). Longitudinal analysis showed that majority of live births, in AIH or IVF groups, were achieved in the first two cycles. Conclusions: In subfertile women with DOR, live birth rates following AIH were significantly lower than IVF, especially for the aged women. Considering the low efficacy of AIH and that majority of live births were achieved in the first two cycles, we suggest no more than two AIH treatment attempts for the aged women with DOR.

Intervention factors associated with environmental stressors resulting from cross-provincial transfers by coal resource-based enterprises.

The environmental stressors associated with the cross-provincial transfer of coal resource-based enterprises (CREs) have become a critical concern for the green, sustainable, and high-quality development of resource-rich areas in central and western regions. This study referred to socioeconomic statistics and carried out an interview survey, literature review, and systematic analysis to clarify the mechanism underlying environmental stressors arising from the cross-provincial transfer of CREs. The intervention factors associated with such environmental stressors were identified, and the study conducted an empirical analysis of relevant data related to the coal-resources industry in three central and western provinces in China for the period 1997-2016. Research findings: (1) The intensity ranking of the influencing factors associated with environmental stressors caused by cross-provincial transfers of CREs has certain rules. The 'level of the enterprise's investment in environmental protection' is the weakest, the 'enterprise's development mode level' is slightly stronger, the 'enterprise scale' is stronger, and 'environmental regulation' is the strongest. (2) Stricter endogenous and exogenous policy regulations for environmental governance in rich coal resource-based regions are associated with weaker negative externalities in respect of resource development and the intensity of stressors. (3) Larger CREs are associated with a better green mining capacity, environmental repair cost advantages, social constraints, self-discipline, and thus, a weaker stress effect. (4) CREs that adopt more superior modes of development that focus on the utilization of the 'three wastes' are associated with a weaker stress effect. (5) The higher the level of investment by CREs in environmental protection technology, facilities, and equipment, the weaker the stress effect. The conclusions of the study can provide a theoretical basis to assist the Chinese government to develop relevant regulations to control inter-provincial transfers by CREs and to thereby diminish environmental stressor effects.

Nitrogen-enriched micro-mesoporous carbon derived from polymers organic frameworks for high-performance capacitive deionization.

Nitrogenization is an effective method for improving the capacitive deionization (CDI) performance of porous carbon materials. In particular, polymer organic frameworks with heteroatom doping, containing an ordered pore structure and excellent electrochemical stability, are ideal precursors for carbon materials for high-performance CDI. In this study, a nitrogen-enriched micro-mesoporous carbon (NMC) electrode was fabricated by carbonizing a Schiff base network-1 at 500, 600, and 700 °C. Scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, N2 adsorption-desorption, the contact angle of water, cyclic voltammetry, and electrochemical impedance spectroscopy were used to characterize the morphological structure, wettability, Brunauer-Emmett-Teller surface areas, and electrochemical performance of the NMCs. The results showed that the NMC carbonized at 600°C achieved the best specific capacitance (152.33 F/g), as well as a high electrosorption capacity (25.53 mg/g) because of its chemical composition (15.57% N) and surface area (312 m2/g). These findings prove that NMC is viable as an electrode material for desalination by high-performance CDI applications.

Electroacupuncture Promotes the Survival of the Grafted Human MGE Neural Progenitors in Rats with Cerebral Ischemia by Promoting Angiogenesis and Inhibiting Inflammation.

Stem cells have the potential as a regenerative therapy for cerebral ischemia by improving functional outcomes. However, cell transplantation has some limitations, including a low rate of the grafted cell survival. There is still a major challenge of promoting the harmonious symbiosis between grafted cells and the host. Acupuncture can effectively improve the functional outcome after cerebral ischemia. The present study evaluated the therapeutic effects and explored the mechanism of combined medial ganglionic eminence (MGE) neural progenitors differentiated from human embryonic stem cells (hESCs) with electroacupuncture (EA) in a bilateral common carotid artery occlusion (2VO) rat model. The results showed that EA could promote the survival of the grafted MGE neural progenitors differentiated from hESCs and alleviate learning and memory impairment in rats with cerebral ischemia. This may have partially resulted from inhibited expression of TNF-α and IL-1ß and increased vascular endothelial growth factor (VEGF) expression and blood vessel density in the hippocampus. Our findings indicated that EA could promote the survival of the grafted MGE neural progenitors and enhance transplantation therapy's efficacy by promoting angiogenesis and inhibiting inflammation.

Chlorobenzene levels, component distribution, and ambient severity in wastewater from five textile dyeing wastewater treatment plants.

Chlorobenzenes (CBs) present in synthetic dyes are discharged into natural waters during the treatment of textile dyeing wastewater, which may have adverse effects on human and environment. In this study, the existence and removal of 12 CBs in different units of five treatment plants were examined. The ecological risk of CBs in textile dyeing wastewater was assessed by ambient severity (AS) and risk quotients (RQs). The results showed that trichlorobenzene, tetrachlorobenzene, pentachlorobenzene and hexachlorobenzene were ubiquitous in textile dyeing wastewater, and their distribution was similar. In one of the plants, the content of hexachlorobenzene was found to be as high as 9.277 µg/L in the raw water, which was an oil-water mixture. In other plants, there was no significant difference in the content and composition of CBs among influent and effluent suggesting that the conventional wastewater treatment plants cannot improve the existence of them. Monochlorobenzene and dichlorobenzene were not detected, which may have been related to strong volatility, biochemical properties, and weak instrument sensitivity. In the treatment process and effluent, trichlorobenzene is the main pollutant and accounted for 39.51% of all CB. CB removal was found only in the anaerobic system, while the aerobic system did not have the corresponding removal effect on CB and total organic carbon. According to ecological risk assessment, CBs in effluent has not been found the significant potential harm to human health (AS < 1), but posed moderate ecological risk to aquatic ecosystem (RQs > 0.1).

Ion-exchange polymers modified bacterial cellulose electrodes for the selective removal of nitrite ions from tail water of dyeing wastewater.

Ion-exchange polymer and modified carbonization bacterial cellulose (CBC) electrodes were fabricated using varying amounts of cation-exchange polymers (glutaric acid (GA) and sulfosuccinic acid (SSA)) and assembled within an asymmetric capacitive deionization unit (p-CDI). The performance of selective NO2- electro-adsorption was studied. The AC/CBC-SSA group showed a better salt adsorption capacity (14.56 mg/g) and nitrite removal efficiency (71.01%) than the AC/CBC-GA (10.72 mg/g, 47.83%) and AC/AC (4.81 mg/g, 12.74%) groups. It was confirmed that the CBC-SSA/GA electrodes enhanced nitrite selectivity and increased the adsorption capacity, and the total amounts of adsorbed anions increased when the applied voltage was increased from 0.8 to 1.2 V, while the molar fraction of nitrate decreased. The competitive and preferential adsorption of anions was further investigated using different binary solutions of anions and occurred in the following sequence: NO2- >SO42- >NO3- >F-≈ Cl-. Furthermore, the p-CDI units were applied to remove nitrite in real wastewater samples, and the results showed that they had excellent reusability and application for use in dyeing wastewater treatment.

[Dynamic inflammatory response in a critically ill COVID-19 patient treated with corticosteroids].

OBJECTIVE: To investigate the effect of corticosteroids therapy on the inflammatory response in a critically ill coronavirus disease 2019 (COVID-19) patient. METHODS: A 55-year old female patient with critical ill COVID-19 was admitted in Taizhou Hospital on January 19, 2020. The patient was treated with methylprednisolone 80 mg on the 2nd day after admission. Thereafter, the dose was adjusted in a timely manner and the therapy lasted for 13 days. The peripheral lymphocyte subsets (CD3+T, CD4+ T, CD8+ T, NK cells, B cells), as well as serum levels of lymphocyte factors (IL-2, IL-4, IL-6, IL-10, TNF-α, IFN-γ) were dynamically monitored. RESULTS: On D1 of admission, the numbers of peripheral blood CD3+ T, CD4+ T, CD8+ T, and NK cells were significantly lower than the normal range. With the improvement of the disease, the numbers of CD3+ T, CD8+ T and CD4 + T cells gradually recovered and showed a linear growth trend (linear fitting equation: Y=18.59X+109.4, P<0.05). On D2 of admission, the patient's IL-6 and IL-10 levels were significantly higher than normal values, IFN-γ was at a normal high value, and then rapidly decreased; IL-2, IL-4, and TNF-α were all in the normal range. On the D6 and D7, the IL-6 and IL-10 decreased to the normal range for the first time. On the D18, the sputum virus nucleic acid test was negative for the first time, and the fecal virus nucleic acid test was still positive; on the D20 the sputum and fecal virus nucleic acid test were both negative. On D34, the patient recovered and was discharged. At the discharge the muscle strength score of the patient was 44 and the daily life ability evaluation was 90. CONCLUSIONS: In the absence of effective antiviral drugs, early use of appropriate doses of corticosteroids in critically ill patient with COVID-19 can quickly alleviate inflammatory response and improve clinical symptoms, however, it may reduce the number of T cells, and to adjust the dose in time is necessary.

C8-modified magnetic graphene oxide based solid-phase extraction coupled with dispersive liquid-liquid microextraction for detection of trace phthalate acid esters in water samples.

Phthalate acid esters (PAEs) are extensively applied in plastic and plastic products, and have caused potential hazards on human and animal health. In this study, a highly sensitive method was proposed for trace detection of selected PAEs in water by gas chromatography-mass spectrometry, after solid-phase extraction (SPE) using octyl (C8)-modified magnetic graphene oxide (MGO-C8) as the adsorbent followed by dispersive liquid-liquid microextraction (DLLME). The prepared MGO-C8 was characterized by Fourier transform infrared spectroscopy (FT-IR), thermo gravimetric analysis (TGA) and vibrating sample magnetometry (VSM). The recoveries of the PAEs using MGO-C8 as the adsorbent were found to be significantly higher those obtained by MGO. The influences of solution pH, adsorption and desorption time, eluent and extractant, and salt addition on the extraction efficiency of PAEs were investigated. Under the optimized conditions, limits of detection (LODs) of 0.5-1.0 ng L-1 for PAEs, and related standard deviations (RSDs) of 4.8-7.5% were obtained. The proposed method was utilized in the detection of trace PAEs in real environmental water samples, with spiked recoveries of 89.5-112.3%, 91.5-105.0% and 98.0-110.0% for DBP, DEHP and DNOP, respectively.

[Application of heterogeneous VIKOR method in surgical selection for a case of rectal cancer].

According to the literature and expert experience, a comprehensive index system of subjective and objective was established, including the patient's condition, the treatment information for the same kind of patients, technical level of the medical team, and the medical conditions. Secondly, in the light of the heterogeneous evaluation information, the comprehensive index weight was computed by combining subjective weight and objective entropy weight. Furthermore, the VIKOR method was applied to deal with heterogeneous evaluation information and obtain the priority of potential surgical treatments. Taking a rectal cancer patient in a general hospital in Hunan Province as an example, the optimal surgical treatment obtained by this method was consistent with the actual treatment. The reliability and effectiveness of the heterogeneous VIKOR method based on probabilistic linguistic term sets are verified by an experimental example of rectal cancer, and the method can be used to help doctors, patients and family members to select the surgical treatments for rectal cancer effectively.

Determination of trace bisphenol A in environmental water by high-performance liquid chromatography using magnetic reduced graphene oxide based solid-phase extraction coupled with dispersive liquid-liquid microextraction.

Bisphenol A (BPA), an endocrine-disrupting chemical, has received much attention from researchers and the general public. In this paper, a novel method of determining BPA at trace levels was developed, using magnetic reduced graphene oxide (rGO-Fe3O4)-based solid-phase extraction coupled with dispersive liquid-liquid microextraction (DLLME), followed by high-performance liquid chromatographic determination. The rGO-Fe3O4 was prepared and then characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, and vibrating sample magnetometry. The greatest saturation magnetization of rGO-Fe3O4 was up to 43.8 emu g-1, which allowed rapid isolation of the rGO-Fe3O4 from solutions upon applying an appropriate magnetic field. The effects of solution pH, adsorbent amount, type and volume of eluent and extraction solvent, extraction time, and salt concentration on the extraction efficiency of BPA were examined and optimized. Under the optimum conditions, an enrichment factor of 5217 and an LOD of 0.01 µg L-1 for BPA were obtained. The reusability of rGO-Fe3O4 for at least 12 repeated cycles without any significant decrease in the extraction recovery of BPA was demonstrated. The proposed method was applied to the determination of BPA in different real water samples, with relative recoveries of 84.8-104.9 % and RSDs of 0.8-8.3 % in the spiked concentration range 1-10 µg L-1.

Wide bandgap mesoporous hematite nanowire bundles as a sensitive and rapid response ethanol sensor.

In this study, α-Fe2O3 nanowires were synthesized using mesoporous SBA-15 silica as the hard templates with the nanocasting method, and then mesoporous α-Fe2O3 nanowire bundles (NWBs) were separated from the well-dispersed α-Fe2O3 nanowires (NWs) by the centrifugation technique. Both samples were characterized by x-ray diffraction, transmission electron microscopy (TEM), nitrogen adsorption/desorption isotherm and UV-vis spectra. All results indicated that the α-Fe2O3 NWBs with mesoporous structure presented a higher BET surface area (95 m(2) g(-1)) and wider bandgap (2.08 eV) than those of α-Fe2O3 NWs (32 m(2) g(-1) and 1.91 eV). The bandgap of α-Fe2O3 NWBs was in accordance with the bulk α-Fe2O3, while the BET surface area was much higher. The results from the gas-sensing measurement revealed that the α-Fe2O3 NWBs based gas sensor exhibited a high sensitivity of 21.7, fast response-recovery of 7.5 s and 1 s, and good selectivity to ethanol at 340 °C. The sensitivity (21.7) for ethanol of α-Fe2O3 NWBs was much better than that of the α-Fe2O3 NWs (12.2), which should be attributed to the higher BET surface area and wider bandgap of α-Fe2O3 NWBs.