Steering Electron-Induced Surface Reaction via a Molecular Assembly Approach.

Electrons not only serve as a "reactant" in redox reactions but also play a role in "catalyzing" some chemical processes. Despite the significance and ubiquitousness of electron-induced chemistry, many related scientific issues still await further exploration, among which is the impact of molecular assembly. In this work, microscopic insights into the vital role of molecular assembly in tweaking the electron-induced surface chemistry are unfolded by combined scanning tunneling microscopy and density functional theory studies. It is shown that the selective dissociation of a C-Cl bond in 4,4″-dichloro-1,1':3',1''-terphenyl (DCTP) on Cu(111) can be efficiently triggered by an electron injection via the STM tip into the unoccupied molecular orbital. The DCTP molecules are embedded in different assembly structures, including its self-assembly and coassemblies with Br adatoms. The energy threshold for the C-Cl bond cleavage increases as more Br adatoms stay close to the molecule, indicative of the sensitive response of the electron-induced surface reactivity of the C-Cl bond to the subtle change in the molecular assembly. Such a phenomenon is rationalized by the energy shift of the involved unoccupied molecular orbital of DCTP that is embedded in different assemblies. These findings shed new light on the tuning effect of molecular assembly on electron-induced reactions and introduce an efficient approach to precisely steer surface chemistry.

Engineered Microrobots for Targeted Delivery of Bacterial Outer Membrane Vesicles (OMV) in Thrombus Therapy.

In the realm of thrombosis treatment, bioengineered outer membrane vesicles (OMVs) offer a novel and promising approach, as they have rich content of bacterial-derived components. This study centers on OMVs derived from Escherichia coli BL21 cells, innovatively engineered to encapsulate the staphylokinase-hirudin fusion protein (SFH). SFH synergizes the properties of staphylokinase (SAK) and hirudin (HV) to enhance thrombolytic efficiency while reducing the risks associated with re-embolization and bleeding. Building on this foundation, this study introduces two cutting-edge microrobotic platforms: SFH-OMV@H for venous thromboembolism (VTE) treatment, and SFH-OMV@MΦ, designed specifically for cerebral venous sinus thrombosis (CVST) therapy. These platforms have demonstrated significant efficacy in dissolving thrombi, with SFH-OMV@H showcasing precise vascular navigation and SFH-OMV@MΦ effectively targeting cerebral thrombi. The study shows that the integration of these bioengineered OMVs and microrobotic systems marks a significant advancement in thrombosis treatment, underlining their potential to revolutionize personalized medical approaches to complex health conditions.

EptA of Riemerella anatipestifer mediates phenotypes involved in colistin resistance and virulence.

Colistin (polymyxin E) is a group of cationic antimicrobial cyclic peptides and is recognized as a last-resort defense against lethal infections with carbapenem-resistant pathogens. In addition to the plasmid-borne mobilized phosphoethanolamine (PEA) transferases, the functional expression of lipid A-modifying enzymes encoded on chromosomes has been attributed to intrinsic bacterial colistin resistance. However, the mechanisms of colistin resistance in Riemerella anatipestifer remain unknown. Herein, the GE296_RS09715 gene-encoded Lipid A PEA transferases (RaEptA) was identified in R. anatipestifer. Genetic and structural analyses revealed that the amino acid sequence of RaEptA shared 26.6%-33.1% similarities with the family of Lipid A PEA transferases (EptA) and MCR-like proteins and have defined 12 residues that contribute to the formation of phosphatidylethanolamine (PE)-recognizable cavities. Comparative analyses of colistin resistance in RA-LZ01 and RA-LZ01ΔRaEptA showed the level of colistin has fallen from 96 µg mL-1 down to 24 ~ 32 µg mL-1 . Site-directed mutagenesis assay of the PE-binding cavity and expression of the mutants reveals that K309-rRaEptA can remodel the surface of Escherichia coli and rendering it resistant to colistin, suggesting this point-mutation of P309K is necessary for EptA-mediated lipid A modification. Moreover, the virulence of RA-LZ01ΔRaEptA was attenuated compared with RA-LZ01 both in vivo and vitro. Taken together, the results represent the RaEptA involved in the colistin resistance and pathogenicity, and the P309K mutation might alter bacterial adaptation and increase the spread of colistin resistance from R. anatipestifer to other gram-negative bacteria. The findings of this study suggest another scenario for the spread of colistin resistance genes and should be considered by a wide audience.

Substituent Positioning Effects on the Magnetic Properties of Sandwich-Type Erbium(III) Complexes with Bis(trimethylsilyl)-Substituted Cyclooctatetraenyl Ligands.

Lanthanide complexes with judiciously designed ligands have been extensively studied for their potential applications as single-molecule magnets. With the influence of ligands on their magnetic properties generally established, recent research has unearthed certain effects inherent to site differentiation due to the different types and varying numbers of substituents on the same ligand platform. Using two new sandwich-type Er(III) complexes with cyclooctatetraenyl (COT) ligands featuring two differently positioned trimethylsilyl (TMS) substituents, namely, [Li(DME)Er(COT1,5-TMS2)2]n (Er1) and [Na(DME)3][Er(COT1,3-TMS2)2] (Er2) [COT1,3-TMS2 and COT1,5-TMS2 donate 1,3- and 1,5-bis(trimethylsilyl)-substituted cyclooctatetraenyl ligands, respectively; DME = 1,2-dimethoxyethane], and with reference to previously reported [Li(DME)3][Er(COT1,4-TMS2)2] (A) and [K(DME)2][Er(COT1,4-TMS2)2] (B), any possible substituent position effects have been explored for the first time. The rearrangement of the TMS substituents from the starting COT1,4-TMS2 to COT1,3-TMS2 and COT1,5-TMS2, by way of formal migration of the TMS group, was thermally induced in the case of Er1, while for the formation of Er2, the use of Na+ in the placement of its Li+ and K+ congeners is essential. Both Er1 and Er2 display single-molecule magnetic behaviors with energy barriers of 170(3) and 172(6) K, respectively. Magnetic hysteresis loops, butterfly-shaped for Er1 and wide open for Er2, were observed up to 12 K for Er1 and 13 K for Er2. Studies of magnetic dynamics reveal the different pathways for relaxation of magnetization below 10 K, mainly by the Raman process for Er1 and by quantum tunneling of magnetization for Er2, leading to the order of magnitude difference in magnetic relaxation times and sharply different magnetic hysteresis loops.

DR6 Augments Colorectal Cancer Cell Growth, Invasion, and Stemness by Activating AKT/NF-κB Pathway.

This study aims to elucidate the role and mechanisms of Death Receptor 6 (DR6), a member of the tumor necrosis factor receptor superfamily, in the malignant progression of colorectal cancer (CRC). The association of DR6 expression levels and CRC patient survival was examined using the CRC cohort data from GEPIA database. The functional role of DR6 in CRC cells was investigated by performing loss-of-function and gain-of-function experiments based on CCK-8 proliferation assay, transwell migration and invasion assay, and sphere-forming assays. Xenograft model of CRC cells in nude mouse was established to evaluate the impact of DR6 knockdown on CRC tumorigenesis. Elevated expression of DR6 was correlated with an unfavorable prognosis in CRC patients. In vitro functional assays demonstrated that silencing DR6 considerably suppressed the proliferation, migration, invasion, and stemness of CRC cells, whereas its overexpression showed an opposite effect. DR6 knockdown also attenuated tumor formation of CRC cells in the nude mice. Mechanistically, silencing DR6 reduced the phosphorylation of AKT and NF-κB in CRC cells, and the treatment with an AKT activator (SC79) abrogated the inhibitory effects of DR6 knockdown on the malignant features of CRC cells. Our data suggest that DR6 contributes to the malignant progression of CRC by activating AKT/NF-κB pathway, indicating its clinical potential as a prognostic marker and therapeutic target for CRC.

Clustering-Evolved Frontier Orbital for Low-Temperature CO2 Dissociation.

In this study, single Ni2 clusters (two Ni atoms bridged by a lattice oxygen) are successfully synthesized on monolayered CuO. They exhibit a remarkable activity toward low-temperature CO2 thermal dissociation, in contrast to cationic Ni atoms that nondissociatively adsorb CO2 and metallic Ni ones that are chemically inert for CO2 adsorption. Density functional theory calculations reveal that the Ni2 clusters can significantly alter the spatial symmetry of their unoccupied frontier orbitals to match the occupied counterpart of the CO2 molecule and enable its low-temperature dissociation. This study may help advance single-cluster catalysis and exploit the unexcavated mechanism for low-temperature CO2 activation.

Value Added Conversion of Ethanol on Morphologically Controlled and Defect-Engineered Titanium Dioxide Nanorods.

Developing an environmentally benign and highly effective strategy for the value-added conversion of biomass platform molecules such as ethanol has emerged as a significant challenge and opportunity. This challenge stems from the need to harness renewable solar energy and conduct thermodynamically unfavorable reactions at room temperature. To tackle this challenge, one-dimensional titanium dioxide photocatalysts have been designed and fabricated to achieve a remarkable photocatalytic selectivity of almost 100 % for transforming ethanol into value-added 1,1-diethoxyethane, contrasting the primary production of acetaldehyde in titanium dioxide nanoparticles. By incorporating a Pt co-catalyst and infusing oxygen vacancies into the one-dimensional catalyst, the ethanol transformation rate was doubled to 128.8 mmol g-1 h-1 with respect to that of its unmodified counterpart (about 66.7 mmol g-1 h-1 ). The underlying mechanism for this high conversion and selectivity resides in the narrowed bandgap of the catalyst and the prolonged lifetime of the photo-generated carriers. This is a promising strategy for the photocatalytic transformation of essential biomass platform molecules that intertwines morphological control and defect engineering.

Molecular insight into on-surface chemistry of an organometallic polymer.

A molecular investigation of Cu-elimination and subsequent C-C coupling of DCTP (4,4''-dichloro-1,1':3',1''-terphenyl)-Cu organometallic (OM) polymers on Cu(111) is conducted by scanning tunneling microscopy and spectroscopy, revealing that the Cu adatoms embedded in the DCTP-Cu chains are located at the hollow and bridge sites on the Cu(111) surface. The difference in the catalytic activities of these surface sites leads to stepwise elimination of Cu adatoms in the OM chains. Moreover, the interchain interaction plays an important role in the Cu-elimination process of the DCTP-Cu chains as well. The interchain steric hindrance, on the one hand, induces the formation of Cu-eliminated intermediates that are scarcely observed in other Ullmann coupling systems, and on the other hand, promotes the cooperative Cu-elimination and C-C coupling of the OM segments in neighboring chains. These findings demonstrate the key role of the molecule-substrate and intermolecular interactions in mediating the reaction processes of the extended molecular systems on the surface.

Cation affinity purification of histidine-tagged proteins.

Protein purification is a basic technology in both biological research and industrial production, and efficient, convenient, economical, and environmentally friendly purification methods have always been pursued. In this study, it was found that alkaline earth metal cations (Mg2+, Ca2+) and alkali metal cations (Li+, Na+, K+) and even nonmetal cations (e.g., NH4+, imidazole, guanidine, arginine, lysine) can precipitate multi-histidine-tagged proteins (at least two tags in a whole protein) at low salts concentrations that are 1-3 orders of magnitude lower than salting-out, and precipitated proteins could be dissolved at moderate concentration of corresponding cation. Based on this finding, a novel cation affinity purification method was developed, which requires only three centrifugal separations to obtain highly purified protein with purification fold similar to that of immobilized metal affinity chromatography. The study also provides a possible explanation for unexpected protein precipitation and reminds researchers to consider the influence of cations on the experimental results. The interaction between histidine-tagged proteins and cations may also have broad application prospects. KEY POINTS: • Histidine-tagged proteins can be precipitated by low-concentrations common cations • A novel nonchromatographic protein purification method was developed • Purified protein can be obtained in pellet form by only three centrifugations.

Individualized treatment decision model for inoperable elderly esophageal squamous cell carcinoma based on multi-modal data fusion.

BACKGROUND: This research aimed to develop a model for individualized treatment decision-making in inoperable elderly patients with esophageal squamous cell carcinoma (ESCC) using machine learning methods and multi-modal data. METHODS: A total of 189 inoperable elderly ESCC patients aged 65 or older who underwent concurrent chemoradiotherapy (CCRT) or radiotherapy (RT) were included. Multi-task learning models were created using machine learning techniques to analyze multi-modal data, including pre-treatment CT images, clinical information, and blood test results. Nomograms were constructed to predict the objective response rate (ORR) and progression-free survival (PFS) for different treatment strategies. Optimal treatment plans were recommended based on the nomograms. Patients were stratified into high-risk and low-risk groups using the nomograms, and survival analysis was performed using Kaplan-Meier curves. RESULTS: The identified risk factors influencing ORR were histologic grade (HG), T stage and three radiomic features including original shape elongation, first-order skewness and original shape flatness, while risk factors influencing PFS included BMI, HG and three radiomic features including high gray-level run emphasis, first-order minimum and first-order skewness. These risk factors were incorporated into the nomograms as independent predictive factors. PFS was substantially different between the low-risk group (total score ≤ 110) and the high-risk group (total score > 110) according to Kaplan-Meier curves (P < 0.05). CONCLUSIONS: The developed predictive models for ORR and PFS in inoperable elderly ESCC patients provide valuable insights for predicting treatment efficacy and prognosis. The nomograms enable personalized treatment decision-making and can guide optimal treatment plans for inoperable elderly ESCC patients.

Single-Cation Catalyst: Ni Cation in Monolayered CuO for CO Oxidation.

It is vital to differentiate catalytic properties between cationic and metallic single atoms at the atomic level. To achieve this, we fabricated well-defined cationic Ni atoms snugged in and metallic Ni atoms supported on monolayered CuO. The Ni cations are chemically inert for CO adsorption even at 70 K but highly active toward O2 dissociation at room temperature. The adsorbed O atoms are active to oxidize incoming CO molecules from the gas phase into CO2, which follows the Eley-Rideal mechanism, in contrast to the Mars-van Krevelen mechanism on CuO-monolayer-supported metallic Ni atoms as well as our previously reported Au and Pt model catalysts. This study helps understand the chemistry of a supported single-metal cation, which is of great importance in heterogeneous catalysis.

Network Meta-Analysis of All Available Regimens Based on Drug-Coated Balloon Angioplasty and Laser Atherectomy for Femoropopliteal In-Stent Restenosis.

PURPOSE: Drug-coated balloon (DCB) angioplasty and laser atherectomy (LA) have been frequently utilized to treat femoropopliteal in-stent restenosis (ISR); however, no studies have concurrently compared available regimens, including DCB, LA+DCB, and LA + plain balloon angioplasty (PB). Therefore, we conducted this network meta-analysis to determine whether there were significant differences in outcomes among these regimens. MATERIALS AND METHODS: A comprehensive search was conducted in PubMed, EMBASE, and the Cochrane library to identify all randomized controlled trials comparing DCB or LA-based regimes with POBA or each other for treating femoropopliteal in-stent restenosis (ISR) from their inception until March 2021. The primary outcome measure was binary restenosis, and secondary outcome measures were target lesion revascularization (TLR) and mortality, evaluated at 6 and 12 months, respectively. Statistical analysis was performed using Aggregate Data Drug Information System (ADDIS) 1.4 software, and all data were graphically summarized using Microsoft Excel software. RESULTS: The final analysis included 11 studies, of which 6 studies compared DCB with PB, 2 studies compared PB vs LA+PB, 2 studies compared DCB vs LA+DCB, and 1 study compared LA+DCB with LA+PB. DCB was better than PB in decreasing binary restenosis at 6 (odds ratio [OR]: 0.22, 95% credible interval [CrI]: 0.04-0.91) and 12 (OR: 0.26, 95% CrI: 0.12-0.50) months. DCB was associated with lower TLR than PB at 6 months (OR: 0.31, 95% CrI: 0.13-0.69). LA+DCB was also superior to PB in treating binary restenosis at 12 months (OR: 6.10, 95% CrI: 1.94-24.41) and TLR at 6 months (OR: 5.32, 95% CrI: 1.43-28.06). There was no statistical difference in mortality between PB, DCB, and LA+PB. DCB and LA+DCB were the first 2 options for reducing binary restenosis and TLR. CONCLUSION: The current network meta-analysis demonstrates that both DCB and LA+DCB are superior to PB alone, and that DCB and LA+DCB may be the preferred treatment options for reducing binary restenosis and TLR. CLINICAL IMPACT: The treatment for femoropopliteal in-stent restenosis (ISR) remains challenging clinical practice. One important reason is that no optimal treatment strategy was available. Drug-coated balloon angioplasty (DCB) and laser atherectomy (LA) have been extensively utilized to treat ISR; however, different combinations of these treatments further confused the clinicians' choices. This network meta-analysis systematically investigated the difference between the currently available treatments regarding therapeutic effects and safety, indicating that DCB and LA+DCB may be the optimal treatment for decreasing the risk of binary restenosis and target lesion revascularization. The results of the current network meta-analysis help to resolve the confusion of clinicians in making the decision.

Effect of SpyTag/SpyCatcher cyclization on stability and refolding of green fluorescent protein.

To study the effect of SpyTag/SpyCatcher cyclization on stability and refolding of protein, we constructed a cyclized green fluorescent protein (SRGFP) and its derivative to act as a linear structure control (L-SRGFP). SRGFP and L-SRGFP showed similar fluorescence characteristics to the wild-type GFP, while compared with GFP and L-SRGFP, the thermal stability and denaturation resistance of SRGFP were improved. The refolding efficiencies of these three denatured proteins were investigated under different pH, temperature and initial protein concentration conditions, and it was found that SRGFP was superior to GFP and L-SRGFP in terms of refolding yield and refolding speed. In the pH range of 8.0-8.5, SRGFP could basically recover all fluorescence, while GFP and L-SRGFP recovered only about 87.52% and 88.58%. When refolded at a high temperature (37 °C), SRGFP still recovered 85.27% of the fluorescence, whereas GFP and L-SRGFP recovered only around 69.43% and 68.45%. At a high initial protein concentration (5 mg/mL), the refolding yield of SRGFP was about 15% higher than that of both GFP and L-SRGFP. These results suggest that the introduction of SpyRing structure (head-to-tail cyclization via SpyTag and SpyCatcher) improved the protein's stability and facilitated the refolding of denatured protein.

Higher intakes of dietary caffeine are associated with 25-hydroxyvitamin D deficiency.

Low serum 25-hydroxyvitamin D [25(OH)D] levels remain a challenge worldwide. While some in vitro studies show a caffeine-induced decrease in vitamin D receptor expression, there is a paucity of research to define the extent of caffeine intake and effects on 25(OH)D levels. Therefore, we aimed to associate dietary caffeine intake with 25(OH)D deficiency through a recognized dataset. Using data collected from the 2005-2006 National Health and Nutrition Examination Survey (NHANES), 25(OH)D levels and dietary caffeine intake were extracted from 13134 individuals (30-47 years, interquartile range). We used one-way ANOVA and chi-square tests for quantitative and qualitative variables, respectively, and performed multivariate logistic regression for four models to assess the odds ratio (OR) of 25(OH)D deficiency (<20 ng/ml or <50 nmol/L) based on quartiles of dietary caffeine intake. Both crude and multivariable models detected higher OR for 25(OH)D deficiency according to the highest intakes of caffeine (15.8±9.5, 51.9±11.9, and 177±156 mg/d) when compared to the reference category (2.19±1.04 mg/d), in which the OR in the highest category of caffeine intake was 1.24 (95% CI: 1.12 to 1.37) and 1.48 (95% CI: 1.16 to 1.78) for the crude model and the most complete multivariable analysis (adjustment for age, sex, race, body mass index, smoking, physical activity, occupation, energy intake, protein intake, and fat intake), respectively. In conclusion, higher dietary intakes of caffeine were associated with 25(OH)D deficiency in a representative sample of the American population, but further investigation is warranted to determine causation.

ARID1A promotes chemosensitivity to gemcitabine in pancreatic cancer through epigenetic silencing of RRM2.

Pancreatic cancer is one of the most common malignancies with very poor prognosis due to its broad resistance to chemotherapy. ARID1A, a subunit of SWI/SNF complex, is involved in pancreatic carcinogenesis through epigenetic silencing of oncogenes. In this study, we aimed to explore whether ARID1A was implicated in the gemcitabine resistance in pancreatic cancer patients via regulating RRM2. We examined the effect of ARID1A depletion on the gemcitabine sensitivity in pancreatic cancer cells and explored the role of RRM2 in ARID1A-mediated pancreatic cancer cells chemosensitivity to gemcitabine. We found that Knockout of ARID1A led to gemcitabine resistance in pancreatic cancer cells, effect of which could be reversed by RRM2, a gemcitabine resistance related gene. ARID1A decreased the transcription of RRM2, and directly bound to the promoter of RRM2. Moreover, expression of RRM2 was negatively correlated with ARID1A in pancreatic cancer tissues. Thus, ARID1A-mediated RRM2 epigenetic suppression is crucial for enhancement of pancreatic cancer chemosensitivity to gemcitabine, and ARID1A could be used as a biomarker to guide the gemcitabine chemotherapy of pancreatic cancer.

The poultry pathogen Riemerella anatipestifer appears as a reservoir for Tet(X) tigecycline resistance.

The transferability of bacterial resistance to tigecycline, the 'last-resort' antibiotic, is an emerging challenge of global health concern. The plasmid-borne tet(X) that encodes a flavin-dependent monooxygenase represents a new mechanism for tigecycline resistance. Natural source for an ongoing family of Tet(X) resistance determinants is poorly understood. Here, we report the discovery of 26 new variants [tet(X18) to tet(X44)] from the poultry pathogen Riemerella anatipestifer, which expands extensively the current Tet(X) family. R. anatipestifer appears as a natural reservoir for tet(X), of which the chromosome harbours varied copies of tet(X) progenitors. Despite that an inactive ancestor rarely occurs, the action and mechanism of Tet(X2/4)-P, a putative Tet(X) progenitor, was comprehensively characterized, giving an intermediate level of tigecycline resistance. The potential pattern of Tet(X) dissemination from ducks to other animals and humans was raised, in the viewpoint of ecological niches. Therefore, this finding defines a large pool of natural sources for Tet(X) tigecycline resistance, heightening the need of efficient approaches to manage the inter-species transmission of tet(X) resistance determinants.

Vaccine design based on 16 epitopes of SARS-CoV-2 spike protein.

The global outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) urgently requires an effective vaccine for prevention. In this study, 66 epitopes containing pentapeptides of SARS-CoV-2 spike protein in the IEDB database were compared with the amino acid sequence of SARS-CoV-2 spike protein, and 66 potentially immune-related peptides of SARS-CoV-2 spike protein were obtained. Based on the single-nucleotide polymorphisms analysis of spike protein of 1218 SARS-CoV-2 isolates, 52 easily mutated sites were identified and used for vaccine epitope screening. The best vaccine candidate epitopes in the 66 peptides of SARS-CoV-2 spike protein were screened out through mutation and immunoinformatics analysis. The best candidate epitopes were connected by different linkers in silico to obtain vaccine candidate sequences. The results showed that 16 epitopes were relatively conservative, immunological, nontoxic, and nonallergenic, could induce the secretion of cytokines, and were more likely to be exposed on the surface of the spike protein. They were both B- and T-cell epitopes, and could recognize a certain number of HLA molecules and had high coverage rates in different populations. Moreover, epitopes 897-913 were predicted to have possible cross-immunoprotection for SARS-CoV and SARS-CoV-2. The results of vaccine candidate sequences screening suggested that sequences (without linker, with linker GGGSGGG, EAAAK, GPGPG, and KK, respectively) were the best. The proteins translated by these sequences were relatively stable, with a high antigenic index and good biological activity. Our study provided vaccine candidate epitopes and sequences for the research of the SARS-CoV-2 vaccine.

Coupling analysis on ecological environment fragility and poverty in South China Karst.

Ecological environment and poverty have a strong spatial coupling. It is of great significance to study the interaction mechanism between them for ecological restoration and targeted poverty alleviation in ecologically fragile areas. Taking Guizhou Plateau, the center of South China Karst, as a research object, this study constructs a multi-dimensional poverty and ecological vulnerability coupling index system and analyses the coupling relationship between ecological environment and poverty from a village scale, using the comprehensive coupling coordination degree model and hot spot analysis method, followed by classifying the types of poverty villages. Our results suggest that in space, the multi-dimensional poverty index is high in the south, north, and northwest of Guizhou, while, the overall ecological environment quality is high in the west and low in the east. Obvious differences are identified in the spatial distribution pattern between the multi-dimensional poverty index and ecological environment quality, with only point overlap. The multi-dimensional poverty index and ecological environmental vulnerability index of most poor villages have little difference, and the coupling degree is high, extreme coupling accounting for 89.60%. The coupling coordination degree is mainly moderate coordination and basic coordination, poverty and ecological environment are not in high harmony. 69.3% of the poverty villages in the Guizhou Province belong to the type of good ecology-general poverty. Therefore, in the process of development-oriented poverty reduction, according to the coupling relationship between ecology and poverty of the poverty villages. more attention is required for economic development in the east of Guizhou and the ecological restoration in the west.

Vertical macro-channel modification of a flexible adsorption board with in-situ thermal regeneration for indoor gas purification to increase effective adsorption capacity.

Adsorption has been used widely to remove indoor volatile organic compounds (VOCs). However, the large diffusion resistance inside traditional granular adsorbents renders a low VOC adsorption rate. This study proposes a modified method to achieve the rapid diffusion into the adsorbent during the initial adsorption period. A thin and flexible adsorption board with a layer of adsorbent coated on a heating film was prepared for in-situ adsorption and regeneration. Then, regular, vertical macro-channels through the adsorption board were fabricated by laser drilling to enhance mass transfer inside the board. Experimental results demonstrated that after modification, the penetration times for formaldehyde and xylene extended from 3.8 to 6.2 h, and from 62 to 99 h, respectively. The effective adsorption capacity of the modified board had increased by a multiple of two for formaldehyde and 1.8 for xylene. A mathematical model was developed and experimentally validated to evaluate the modification effect for more adsorbent-pollutant pairs. The results showed that the amplification of effective adsorption capacity was positively correlated with the Da/(K·De) parameter; this is the diffusion resistance ratio prior to and following the modification. A spectrogram of adsorbent-pollutant pairs was plotted to guide the modification. This simple macro-channel modification of the adsorption board may be used as an alternative design for adsorption applications in indoor air purification.

Laparoscopic specimen extraction in vitro: preliminary experience.

BACKGROUND: The last procedure performed by the surgeon in laparoscopic surgery is to extract the specimen through the smallest incision possible. This experiment aimed to explore the maximum diameter of specimens that can be extracted through auxiliary incisions of different lengths and shapes by in vitro physical experiments. MATERIALS AND METHODS: We used the abdominal wall with the muscle layer, fixed on a square wooden frame, to simulate the human abdominal wall. Then, specimen extraction ports were made with circular, inverted Y-shaped and straight-line incisions of different sizes and lengths, and specimens of different sizes were made from tissues of different species. These specimens were extracted from different incisions with a force gauge. The tension value (N) was measured, and records were made of the length or diameter of the smallest auxiliary incision through which a given specimen could pass, as well as the largest specimen diameter that could pass through an incision of a given size. This experiment provides us with preliminary experience-based knowledge of how to choose the appropriate auxiliary incision for surgical specimen extraction according to the diameter of the specimen. RESULTS: The maximum diameters of specimens that could be extracted with circular ostomy diameters of 2.4, 2.7 and 3.3 cm were 4.0, 4.5 and 6.0 cm, respectively. Specimens with diameters of 6.0, 8.0 and 10.0 cm could be extracted through inverted Y-shaped incisions with a length around the umbilicus of 1 cm and an extension length of 1.0, 3.0, and 4.0 cm, respectively. Moreover, these same specimens could be extracted through inverted Y-shaped incisions with a length around the umbilicus of 2 cm and extension lengths of 0.0, 1.0 and 2.0 cm. Tough tissue specimens (made from chicken gizzards) with diameters of 1.0, 2.0, 4.0 and 6.0 cm, respectively, could be removed through straight-line incisions measuring 1.0, 2.0, 3.0 and 4.0 cm in length. CONCLUSION: Along with preoperative imaging, surgical planning and trocar position, the shape and length of auxiliary incisions can be used to improve the extraction of specimens via laparoscopic surgery.