Search

Abstract: New composite membranes were prepared by solution casting from sulfonated poly(ether ether ketone), poly(vinylidene fluoride) and phosphotungstic acid. Their structures were characterized using XRD, DSC and FT-IR. The permeability of methanol, ethanol and dimethyl ether in composite membranes ranged from 1.9 to 3.7×10−7, 7.4 to 20×10−8 and 1.6 to 3.2×10−8 cm2/s, respectively. These values were about or more than one order of magnitude lower than those of Nafion® 117 membrane measured under the same condition. The water uptake and the swelling ratio of composite membranes were also studied, and composite membranes showed good water stability within measurement range of temperature. Higher selectivity values were observed for composite membranes compared with Nafion® 117 membrane. [Copyright &y& Elsevier]

Abstract: Alternanthera philoxeroides biomass, a type of freshwater macrophyte, was used for the sorptive removal of Ni(II), Zn(II) and Cr(VI) from aqueous solutions. Variables of the batch experiments include solution pH, contact time, particle size and temperature. The biosorption capacities are significantly affected by solution pH. Higher pH favors higher Ni(II), Zn(II) removal, whereas higher uptake of Cr(VI) is observed as the pH is decreased. A two-stage kinetic behavior is observed in the biosorption of Ni(II), Zn(II) and Cr(VI): very rapid initial biosorption in a few minutes, followed by a long period of a slower uptake. It is noted that an increase in temperature results in a higher Ni(II), Zn(II) and Cr(VI) loading per unit weight of the sorbent. Decreasing the particle sizes of the Alternanthera philoxeroides biomass leads to an increase in the Ni(II), Zn(II) and Cr(VI) uptake per unit weight of the sorbent. All isothermal data are fairly well fitted with Langmuir equations. The thermodynamic parameter, ΔG°, were calculated. The negative ΔG° values of Cr(VI), Ni(II) and Zn(II) at various temperatures confirm the adsorption processes are spontaneous. [Copyright &y& Elsevier]

Abstract: Sulfonated poly(ether ether ketone) (SPEEK) membranes were modified with chemically in situ polymerized polypyrrole (PPy). The effects of temperature and methanol concentration on the solution uptake and the swelling ratio of SPEEK/PPy membranes were investigated. The solution uptake and the swelling ratio of the membranes decreased upon the incorporation of PPy. When the methanol concentration increased, both the solution uptake and the swelling ratio increased to a maximum, and then decreased. FT-IR, XRD, DSC and TGA were used to characterize the modified membranes. The methanol permeability of modified SPEEK membranes decreased upon the incorporation of PPy, and higher selectivity values were found for SPEEK/PPy membranes in comparison with pure SPEEK and Nafion® 117 membranes. [Copyright &y& Elsevier]

Abstract: The aim of this study is to investigate the role of proteasome in the pathogenesis of lung injury induced by intestinal ischemia/reperfusion (I/R) by examining the effect of the proteasome inhibitor lactacystin on neutrophil infiltration, intracellular adhesion molecule-1 (ICAM-1) expression and nuclear factor kappa B (NF-κB) activation. Thirty-two Wistar rats were divided into (1) control, (2) intestinal I/R, (3) 0.2 mg/kg lactacystin pretreated, and (4) 0.6 mg/kg lactacystin pretreated groups (n =8). Injuries in lung and intestine were induced by intestinal I/R, and were characterized by histological edema, hemorrhage and infiltration of inflammatory cells. The results showed a significant increase in serum creatine kinase B (CK-B) and lung water content in intestine and lung injuries. As compared with the control group, the myeloperoxidase (MPO) activity in intestine and lung as well as the serum TNF-α level increased significantly in intestinal I/R group. Simultaneously, expression of ICAM-1 and NF-κB p65 was also observed in the I/R group. Pre-treatment with lactacystin markedly reduced 20S proteasome activity in circulating white blood cells and ameliorated intestine and lung injuries. These results demonstrated that the proteasome participates in the pathogenesis of lung injury induced by intestinal I/R. Lactacystin as a proteasome inhibitor can prevent this kind of injury by decreasing ICAM-1 and TNF-α production via the inhibition of NF-κB activation. [Copyright &y& Elsevier]

Abstract: The identification of structural damage is an important objective of health monitoring for civil infrastructures. Frequently, damage to a structure may be reflected by a change of some system parameters, such as a degradation of the stiffness. In this paper, we propose an online sequential weighted Least Squares Support Vector Machine (LS-SVM) technique to identify the structural parameters and their changes when vibration data involve damage events. It efficiently updates a trained LS-SVM by means of incremental updating and decremental pruning algorithms whenever a sample is added to, or removed from, the training set, and robustness is improved by the use of an additional weighted LS-SVM step. This method overcomes the drawback of sparseness lost within the LS-SVM and makes LS-SVM for online system identification possible. The proposed method is capable of tracking abrupt or slow time changes of the system parameters from which the damage event and the severity of the structural damage can be detected and evaluated. Simulation results for tracking the parametric non-stationary changes of non-linear hysteretic structures are presented to demonstrate the application and effectiveness of the proposed technique in detecting the structural damage. [Copyright &y& Elsevier]

The article presents a study which examines the impact of introducing rosuvastatin calcium on direct and indirect costs among patients at high risk for coronary heart disease. All patients in the MarketScan Health and Productivity Management Database who had evidence of coronary heart disease and diabetes were the subjects. An economic simulation model was then developed to project the number of cardiovascular events and associated direct and indirect costs under varying treatment scenarios. Through the study, it was revealed that an uptake of rosuvastatin by 11 percent of high-risk patients would result in eight fewer cardiovascular events, thus having a net savings of $0.85 million in direct medical costs and a net savings of $36, 404 in productivity loss over a period of 5 years.

This study challenged the current conceptualization of social support as a static process and attempted to explore how the sources and types of social support unfolded over time during mainland Chinese immigrant women's first year of resettlement in Hong Kong. A longitudinal qualitative method was used and 15 immigrant women were recruited. In-depth interviews using a semi-structured interview guide were conducted at three-monthly intervals. Results supported our view on the “stages within stage” assumption of the resettlement period of the migration-integration process. In the first quarter of resettlement, immigrant women mobilized a great deal of instrumental and information support from family members and kin to resolve survival issues such as finances, housing and childcare. However, the demand for instrumental support declined over time, and the need for emotional support appeared to peak at the second stage of the resettlement period. Fellow immigrant women were found to be the most significant providers of information, emotional and social companionship support to immigrant women throughout the resettlement period while the supporting roles of husbands and kin diminished. Lastly, immigrant women were less inclined to seek help from formal networks and rarely sought support from neighbors and co-workers. Socio-economic and cultural reasons were used to explain these differential support patterns during immigrants' first year of resettlement in Hong Kong, and implications for social work practices were discussed. [ABSTRACT FROM PUBLISHER]

Abstract: A simple and mild method for the deprotection of heteroaromatic carbamates via methanolysis using a catalytic amount of base such as sodium methoxide, DBU, or Verkade’s base (proazaphosphatranes) is presented. Carbamate protecting group of an aliphatic amine is not affected under these conditions. [Copyright &y& Elsevier]

Abstract: Blend membranes were obtained by solution casting from poly(vinylidene fluoride) (PVDF) and sulfonated poly(ether ether ketone) (SPEEK) in N,N-dimethylacetamide (DMAc). DSC and XRD were used to characterize the structure of the blend membranes. The effect of PVDF content on the membrane properties was investigated. The methanol permeability, water uptake and the swelling ratio of blend membranes decreased with the increase of PVDF content. Though the proton conductivity decreased upon the addition of PVDF, they were still comparable to that of Nafion® 117 membrane. Higher selectivities were also found for most blend membranes in comparison with Nafion® 117 membrane. The effect of methanol concentration on solution uptake, swelling ratio and methanol permeability of the blend membranes was also studied. [Copyright &y& Elsevier]

This study challenged the current conceptualization of social support as a static process and attempted to explore how the sources and types of social support unfolded over time during mainland Chinese immigrant women's first year of resettlement in Hong Kong. A longitudinal qualitative method was used and 15 immigrant women were recruited. In-depth interviews using a semi-structured interview guide were conducted at three-monthly intervals. Results supported our view on the "stages within stage" assumption of the resettlement period of the migration-integration process. In the first quarter of resettlement, immigrant women mobilized a great deal of instrumental and information support from family members and kin to resolve survival issues such as finances, housing and childcare. However, the demand for instrumental support declined over time, and the need for emotional support appeared to peak at the second stage of the resettlement period. Fellow immigrant women were found to be the most significant providers of information, emotional and social companionship support to immigrant women throughout the resettlement period while the supporting roles of husbands and kin diminished. Lastly, immigrant women were less inclined to seek help from formal networks and rarely sought support from neighbors and co-workers. Socio-economic and cultural reasons were used to explain these differential support patterns during immigrants' first year of resettlement in Hong Kong, and implications for social work practices were discussed. [ABSTRACT FROM AUTHOR]

Abstract: The interaction between integrins and extracellular matrix proteins play an important role in the regulation of hematopoiesis. Human hematopoietic progenitor cells express very late antigen-4 (VLA-4) and VLA-5, which mediate their interaction with fibronectin by recognizing the connecting segment-1 (CS-1 and RGD motifs, respectively. In this study, we investigated the ex vivo expansion of human umbilical cord blood (UCB) CD34+ cells on synthetic substrates surface-immobilized with peptides containing the CS-1 binding motif (EILDVPST) and the RGD motif (GRGDSPC). These peptides were covalently conjugated to poly(ethylene terephthalate) (PET) film at a surface density of 2.0–2.3nmol/cm2. UCB CD34+ cells were cultured for 10 days in serum-free medium supplemented with recombinant human thrombopoietin, stem cell factor, flt3-ligand and interleukin 3. The highest cell expansion fold was observed on the CS-1 peptide-modified surface, where total nucleated cells, total colony forming unit, and long-term culture initiating cells were expanded by 589.6±58.6 (mean±s.d.), 76.5±8.8, and 3.2±0.9-fold, respectively, compared to unexpanded cells. All substrates surface-immobilized with peptides, including the control peptides, were more efficient in supporting the expansion of CD34+, CFU-GEMM and LTC-ICs than tissue culture polystyrene surface. Nevertheless, after 10-days of ex vivo expansion from 600 CD34+ cells, only cells cultured on CS-1-immobilized surface yielded positive engraftment, even though the frequency was low. PET surface immobilized with RGD peptide was less efficient than that with CS-1 peptide. Our results suggest that covalently immobilized adhesion peptides can significantly influence the proliferation characteristics of cultured UCB CD34+ cells. [Copyright &y& Elsevier]

Abstract: Partially sulfonated poly(etheretherketone) (SPEEK) samples were prepared by modification of corresponding poly(etheretherketone) (PEEK) with concentrated sulfuric acid. Membranes cast from these materials were evaluated as polymer electrolytes for direct methanol fuel cells (DMFCs). SPEEK membranes were characterized by 1H NMR, FT-IR and TGA. The transverse proton conductivities increased from 4.1 to 9.3×10−3 S/cm with the increase of the degree of sulfonation (DS) from 0.59 to 0.93. These values were comparable with that of Nafion 117 membrane (1.0×10−2 S/cm) measured under the same condition. Nearly one order magnitude difference between transverse conductivity and longitudinal conductivity was found. The methanol permeabilities of the SPEEK membranes were all lower than that of Nafion 117 membrane. The effects of temperature and methanol concentration on the methanol permeability were also studied. In addition, the selectivities of the SPEEK membranes for protons and methanol were all higher than that of Nafion 117 membrane. [Copyright &y& Elsevier]

The soil bacterium Sinorhizobium meliloti establishes nitrogen-fixing symbiosis with its leguminous host plant, alfalfa, following a series of continuous signal exchanges. The complexity of the changes of alfalfa root structures during symbiosis and the amount of S. meliloti genes with unknown functions raised the possibility that more S. meliloti genes may be required for early stages of the symbiosis. A positive functional screen of the entire S. meliloti genome for symbiotic genes was carried out using a modified in vivo expression technology. A group of genes and putative genes were found to be expressed in early stages of the symbiosis, and 23 of them were alfalfa root exudate inducible. These 23 genes were further separated into two groups based on their responses to apigenin, a known nodulation (nod) gene inducer. The group of six genes not inducible by apigenin included the lsrA gene, which is essential for the symbiosis, and the dgkA gene, which is involved in the synthesis of cyclic β-1,2-glucan required for the S. meliloti-alfalfa symbiosis. In the group of 17 apigenin-inducible genes, most have not been previously characterized in S. meliloti, and none of them belongs to the nod gene family. The identification of this large group of alfalfa root exudate-inducible S. meliloti genes suggests that the interactions in the early stages of the S. meliloti and alfalfa symbiosis could be complex and that further characterization of these genes will lead to a better understanding of the symbiosis. [ABSTRACT FROM AUTHOR]

Rice bran, an agricultural by-product, was used for the removal of zinc ions from aqueous solution. The work considered the determination of zinc-biomass equilibrium data in batch system. These studies were carried out in order to determine some operational parameters of zinc sorption such as the time required for the Zinc-biosorbent equilibrium, the effects of biomass particle size, pH, and temperature. The results showed that pH has an importance effect on zinc biosorption capacity. The biosorbent size also affects the zinc biosorption capacity. The sorption process follows pseudo-second-order kinetics. The intraparticle diffusion may be the rate-controlling step involved in the adsorption zinc ions onto the rice bran up to 30 min. The equilibrium data could be best fitted by the Langmuir sorption isotherm equation over the entire concentration range (40–160 mg/dm 3 ). Thermodynamic parameters, such as ?G°, ?H°, ?S°, have been calculated. The thermodynamics of zinc ion/rice bran system indicate spontaneous and endothermic nature of the process. [ABSTRACT FROM AUTHOR]

To investigate the influences of the geometries of pendant carboxylate ligands and some intramolecular/intermolecular weak interactions on the structures of transition metal complexes, five new Cd(II) complexes, Cd2(HL1)2(L2)4 (1), Cd2(HL1)2(L3)4 (2), {[Cd2(HL1)(L4)4(H2O)2](H2NH}∞ (3), [Cd(L1)(L5)]∞ (4), and Cd2(L1)2(HL1)2(L4)2 (5) (HL1 = 3-(2-pyridyl)pyrazole, HL2 = benzoic acid, HL3 = naphthalene-carboxylic acid, HL4 = 9-anthracene-carboxylic acid, and HL5 = isonicotinic acid), have been synthesized and structurally characterized by elemental analyses, IR spectroscopy, and single-crystal X-ray diffraction analyses. 1 and 2 have a similar dinuclear structure, which is further assembled to form a one-dimensional (1D) chain by π···π stacking and/or hydrogen-bonding interactions. 3 possesses a 1D chain structure that is further interlinked via intermolecular π···π stacking, resulting in a two-dimensional (2D) network, while 4 has a 2D (4,4) network with channel dimension of 9.34 × 9.34 Å2 and further assembles into a three-dimensional (3D) network by interlayer π···π stacking. 5 also possesses a dinuclear structure and then forms a 2D network through intermolecular π···π stacking and C−H···O hydrogen-bonding interactions. Interestingly, 3 and 5 were obtained simultaneously in the same reaction system. The structural differences of those complexes show the influences of the geometries of the pendant carboxylate ligands. This result also shows that intramolecular/intermolecular weak interactions play important roles in the formation of coordination architectures, especially in the aspect of linking multinuclear discrete subunits or low-dimensional entities into high-dimensional supramolecular frameworks. In addition, complexes 1, 2, and 4 exhibit blue emission in the solid state at room temperature. [ABSTRACT FROM AUTHOR]

Abstract: Six Ru(II)bis(tpy) (tpy=2,2′:6′,2″-terpyridine) complexes, functionalized with one or two 2-naphthyl, 1-pyrenyl, or 9-anthracenyl at 4′-position of terpyridine respectively, were investigated with emphasis on their 1O2 generation quantum yields and photocleavage capabilities on DNA. For naphthyl and pyrenyl modified complexes, the lowest energy excited state is 3MLCT, and therefore they behave very similarly to the parent complex, [Ru(tpy)2]2+, having very low 1O2 generation quantum yields. In contrast, for anthracenyl modified complexes, the lowest energy excited state is anthracene-localized 3ππ * state, as a result, they exhibit extremely high 1O2 generation quantum yields (0.96 and 0.71 for bis- and mono-substituted complexes, respectively) and potent photodamage abilities on calf thymus DNA, suggesting their promising applications in 1O2-involved processes, such as DNA photocleavage. [Copyright &y& Elsevier]

This paper presents a new multi-step predictive controller based on neural networks and researches the adaptability of the predictive controller for a pneumatic position servo system which has some typical characteristics of non-linearity and time-varying. A diagonal recurrent neural network (DRNN) is used to predict the system output of the multi-step ahead directly. According to the intrinsic defects of a back-propagation (BP) algorithm that cannot update network weights incrementally, a new hybrid learning algorithm combining the temporal differences (TD) method with the BP algorithm to train the DRNN is put forward. A three-layer feedforward BP neural network is used as a non-linear rolling optimal controller to realize the optimization of control input of the next step according to a single-value predictive control algorithm to simplify computation. Simulation and experimental results indicate that the proposed predictive controller is suitable for real-time control of a pneumatic position servo system because of its characteristics of a simple algorithm, fast calculation of the control input and good tracking effects. [ABSTRACT FROM AUTHOR]

The present work describes a simple way of synthesizing multifunctional compounds by α‐addition of 1,3‐dicarbonyl compounds to acetylenic ketones catalyzed by triphenylphosphine in moderate to good yields. [ABSTRACT FROM AUTHOR]

Abstract: Two new Cd(II) complexes with a 3-(2-pyridyl)pyrazole-based ligand, [Cd(L)2(SCN)2] (1) and {[Cd(L)2N3](ClO4)} n (2) (L=3-(2-pyridyl)pyrazol-1-ylmethylbenzene) were synthesized and structurally characterized by elemental analyses, IR and single crystal X-ray diffraction analysis. Complex 1 crystallizes in the monoclinic system, space group C2/c, with a=14.833(3), b=13.790(3), c=15.970(3) Å, β=110.89(3)° and Z=4, while 2 crystallizes in the monoclinic system, space group P21/c, with a=13.622(4), b=23.286(7), c=10.547(3) Å, β=111.084(6)° and Z=4. In the two complexes, the Cd(II) centers are coordinated by six nitrogen atoms, in which four from two distinct L ligands and two from thiocyanato (1) or azido (2) anions. Complex 1 has a mononuclear structure, whereas 2 has a 1D chain structure bridged by azido anions. In 2, the azido adopts a μ-1,3-trans coordination mode, which is not common in the azide Cd(II) complexes. In addition, in the structure of 2, the 1D chains were further assembled into a quasi-3D supramolecular network by the C–H⋯O hydrogen-bonding interactions. The structural difference of the two complexes is attributable to the different anions, which have different coordination natures. [Copyright &y& Elsevier]

Abstract: Synthetic oligonucleotides had been employed in DNA repair and promised great potentials in gene therapy. To test the ability of single-stranded oligonucleotide (SSO)-mediated gene repair within a chromosomal site in human cells, a HeLa cell line stably integrated with mutant enhanced green fluorescence protein gene (mEGFP) in the genome was established. Transfection with specific SSOs successfully repaired the mEGFP gene and resulted in the expression of functional fluorescence proteins, which could be detected by fluorescence microscopy and FACS assay. Western blot showed that EGFP was only present in the cells transfected with correction SSOs rather than the control SSOs. Furthermore, DNA sequencing confirmed that phenotype change resulted from the designated nucleotide correction at the target site. Using this reporter system, we determined the optimal structure of SSO by investigating the effect of length, modifications, and polarities of SSOs as well as the positions of the mismatch-forming nucleotide on the efficiency of SSO-mediated gene repair. Interestingly, we found that SSOs with mismatch-forming nucleotide positioned at different positions have varying potencies that homology at the 5′-end of SSOs was more crucial for the SSO’s activity. These results provided guidance for designing effective SSOs as tools for treating monogenic inherited diseases. [Copyright &y& Elsevier]

Abstract: Longimicin C, a naturally occurring annonaceous acetogenin possessing a C 2-symmetrical bis-THF moiety and a short hydrocarbon chain between its THF-containing region and a terminal γ-lactone, was synthesized for the first time. The total synthesis was successfully achieved by an iterative acetylene–epoxide coupling strategy. d-Mannitol was used to establish the bis-THF-containing segment, in which the additional stereochemistries were introduced by Sharpless dihydroxylations and intramolecular Williamson etherifications. Regioselective epoxide-openings by the appropriate terminal acetylenes allowed coupling and elaboration of all four fragments including the introduction of three essential hydroxyls into the proper sites of the target skeleton. [Copyright &y& Elsevier]

Abstract: Centella asiatica, is mainly found in the south of Asia and the southern hemisphere. The pectin was extracted from C. asiatica and isolated by anion-exchange and gel-filtration chromatography with TLC and GLC analyses. It contained arabinose, rhamnose, galactose, xylose and galacturonic acid. The structural features were elucidated by partial acid hydrolysis, enzymatic degradation, methylation, carboxyl-reduction, NMR spectroscopy and ESI-MS experiments. The backbone was presumed to contain 1, 4-linked α-d-GalA and 1, 2/1, 2, 4-linked α-l-Rha with RG-I and homogalacturonan (HG) types. The side chains were neutral chains including arabinosyl, arabinogalactosyl and xylosyl chains. Most of the side chains were attached to Rha, while partial residues were presumed to link to GalA. 14% GalA residues in backbone contained acetyl groups. With deacetylation and carboxyl-reduction, the pectin and its degraded product showed immuno-stimulating activity to different extent in vitro. These results indicated that the carboxyl and acetyl groups play important roles in the expression of immunological activity. [Copyright &y& Elsevier]

Targeted gene modification mediated by single-stranded oligonucleotides (SSOs) holds great potential for widespread use in a number of biological and biomedical fields, including functional genomics and gene therapy. By using this approach, specific genetic changes have been created in a number of prokaryotic and eukaryotic systems. In mammalian cells, the precise mechanism of 550-mediated chromosome alteration remains to be established, and there have been problems in obtaining reproducible targeting efficiencies. It has previously been suggested that the chromatin structure, which changes throughout the cell cycle, may be a key factor underlying these variations in efficiency. This hypothesis prompted us to systematically investigate SSO-mediated gene repair at various phases of the cell cycle in a mammalian cell line. We found that the efficiency of SSO-mediated gene repair was elevated by ≈10-foId in thymidine-treated S-phase cells. The increase in repair frequency correlated positively with the duration of SSO/thymidine coincubation with host cells after transfection. We supply evidence suggesting that these increased repair frequencies arise from a thymidine-induced slowdown of replication fork progression. Our studies provide fresh insight into the mechanism of SSO-mediated gene repair in mammalian cells and demonstrate how its efficiency may be reliably and substantially increased. [ABSTRACT FROM AUTHOR]

A new sorbent (rice bran) for removing Cu2+ from aqueous solution has been investigated. The experimental results were fitted to the Langmuir, Freundlich, Temkin and Redlich–Peterson isotherms to obtain the characteristic parameters of each model. Langmuir, Temkin and Redlich–Peterson isotherms were found to represent the measured sorption data. The maximum sorption capacity of Cu2+ on the rice bran was 33.58 mg/g according to the evaluation of using the Langmuir equation. [Copyright &y& Elsevier]

The applicability of a non-point source pollution model-SWAT(soil and water assessment tools) in a large river basin with high sediment runoff modulus(770 t/km² in the Yellow River) was examined. The basic database, which includes DEM, soil and landuse map, weather data, and land management data, was established for the study area using GIS. A two-stage "Brute Force" optimization method was used to calibrate the parameters with the observed monthly flow and sediment data from 1992 to 1997. In the process of calibration automated digital filter technique was used to separate direct runoff and base flow. The direct runoff was firstly calibrated, and the base flow, then the total runoff was matched. The sediment yield was calibrated to match well. Keeping input parameters set during the calibration process unchanged, the model was validated with 1998-1999's observed monthly flow and sediment. The evaluation coefficients for simulated and observed flow and sediment showed that SWAT was successfully applied in the study area: relative error was within 20% , coefficient of determination and Nash-Suttcliffe simulation efficiency were all equal to or above 0.70 during calibration and validation period. [ABSTRACT FROM AUTHOR]

The bioactivity screening of fractions from two inter-tidal sponges collected from the north of China Yellow Sea and one sponge collected from the South Chinese Sea was reported in this study. In sponge Hymeniacidon perleve there were 9 fractions out of 15 from CHCl3 extract with anti Staphylococcus aureus activity, 9 fractions out of 19 from BuOH extract with anti Escherichia coli activity, and three fractions from CHCl3 extract which had moderate to strong activity in inhibiting Bacillus subtilis, Candida albicans, and Aspergilus niger. The fractions of Reniochalina sp. showed bioactivity against bacteria and fungi. The fractions of Acanthella acuta Schmidt showed bioactivity against S. aureus and fungi. One compound from H. perleve obtained by the bioactively directing isolation was tested for bioactivity against the human hepatoma cell line Qgy7701 (IC50 10.1 μg/ml), Burkitt''s lymphoma cell line Raji (IC50 9.76 μg/ml) and chronic myelogenous leukemia K562 (IC50 1.90 μg/ml). [Copyright &y& Elsevier]

S3A was a RG-I pectin isolated from Centella asiatica that contained Rha, Ara, Gal, Glc and GalA in molar ratio of 1.0:0.6:1.5:0.2:1.1 and had been found to have a backbone composed mainly of the disaccharide repeat unit, →4)-α-d-GalpA-(1→2)-α-l-Rhap-(1→. Based on methylation analysis, NaIO4 oxidation, partial acid hydrolysis and lithium-treatment, the structural features were elucidated. Side chains of S3A were predominantly linked to O-4 of 1,2,4-linked α-l-Rhap. The side chains are comprised of arabinosyl chains, galactosyl chains, arabinogalactosyl chains and short glucosyl chains. A total of 45% Rhap in the backbone was substituted by side chains. The arabinosyl residues were mostly distributed in the arabinosyl side chains. According to the immunological results of S3A and its degraded derivatives, S3A had no immunological activity, but its derivatives had immuno-stimulating activities to some extent. [Copyright &y& Elsevier]

OBJECTIVE: To review the clinical and endoscopic features, and outcome of ischemic colitis. METHODS: Sixty cases with the diagnosis of ischemic colitis were retrospectively analyzed. All the patients were under observation in hospital and most of them underwent colonoscopy at least twice: once for diagnosis and then follow-up after treatment. The demographic data, presenting symptoms, endoscopic findings, laboratory tests, and treatment were reviewed. RESULTS: Fifty-two of the 60 cases were over 50 years old (87%; mean age, 59.9 years): 40 female, 20 male (2 : 1); 76.0% of these patients had a coexistent disease such as a cardio-cerebrovascular disorder, diabetes, hematologic diseases or a previous history of abdominal surgery. Abdominal pain (57/60, 95%), hematochezia (55/60, 91.7%), and diarrhea (26/60, 43.3%) were the main complaints. Lesions seen on colonoscopy were more commonly located in the left colon (46/60, 79.3%) and rectum (5/60, 8.6%), and were characteristically segment-distributed, including hemorrhagic edematous mucosa, erosions, ulcerations, pseudopolyps, and stricture. Ultrasonography revealed colonic wall thickening in 13 cases (13/55, 21.7%), and small to moderate ascites was detected in 4 cases (4/55, 7.3%). In this cohort, most of the patients recovered (49/60, 81.7%) or improved (10/60, 16.7%) after conservative treatment. Only one patient who had a myocardial infarction prior to the onset of the ischemic colitis, died from peritonitis complicated with septic shock. Progress and outcome were associated with the patient's age, severity of the lesions, clinical course, underlying diseases and the complications. CONCLUSION: Colonoscopy is safe and helpful in the early diagnosis of ischemic colitis. Nongangrenous colonic ischemia usually requires only medical management and is associated with a good prognosis. [ABSTRACT FROM AUTHOR]

An extensive literature survey of over 17 Journals was carried out on Chinese sponges and their natural products in the period from 1980 to 2001. This review is thus intended to provide the first thorough overview of research on marine sponges from China Ocean territories. Information is provided about the rather-limited taxonomic study of Chinese marine sponges, with an analysis on their distribution and diversity. Research findings on the natural products and their bioactivity screening from Chinese sponges are summarized. The weaknesses, gaps and problems in the past R&D program of Chinese sponges are identified, which point to the future opportunities in exploiting these huge untapped sponge resources. The report is expected to serve as an entry point for understanding Chinese sponges and for furthering R&D on their bioactive compounds for new drug development. [Copyright &y& Elsevier]

The tumor necrosis factor-related apoptosis-inducing ligand (TRAIL/Apo 2L) is a novel cytotoxic ligand belonging to TNF superfamily. Among TRAIL receptors, death receptor 4 (DR4) and DR5 containing death domain (DD) in their cytoplasmic region mediate apoptosis-signaling upon TRAIL binding, while decoy receptor 1 (DcR1) and DcR2 with a truncated or non-functional DD play "decoy" role. The interaction of TRAIL and TRAIL receptors plays important roles both in immunoregulation and immune pathogenesis of some diseases. In this study, we raised hybridomas secreting monoclonal antibodies against TRAIL (FMU1.1, 1.2, 1.3), DR4 (FMU1.4), DR5 (FMU1.5, 1.6), DcR1 (FMU1.7) and DcR2 (FMU1.8, 1.9). These MAbs could be used for fluorescent staining and flow cytometry (FCM) analysis as well as immunohistochemistry (IHC). Moreover, FMU1.1, 1.3, 1.4 and 1.5 could be used as coating antibodies paring corresponding polyclonal antibodies to develop sandwich ELISAs to quantitate the soluble TRAIL (sTRAIL), sDR4 or sDR5 in serum samples respectively. In addition, cross-linking of DR4/DR5 by FMU1.4 or FMU1.5 MAbs could induce apoptosis of some DR4/DR5-expressing tumor cells. Thus, this set of monoclonal antibodies against TRAIL or TRAIL receptors may be useful in expression phenotypic and functional study of TRAIL and TRAIL receptors. [ABSTRACT FROM AUTHOR]

The present study reports changes in synaptic function and plasticity [long-term potentiation (LTP)] in a recently developed mouse model of Alzheimer''s disease (CRND8 line) harboring a double amyloid precursor protein mutation (APPswe/ind). In 9-week-old preplaque transgenic (Tg) mice brain slices, basal synaptic function in the hippocampal CA1 area was unchanged. Only one of three different LTP induction protocols revealed early influence of genotype on synaptic plasticity. By 20 weeks of age, there were numerous plaques in the hippocampus from Tg mice associated with more robust evidence for genotype-related effects in synaptic function. Field potential maximum slope was consistently decreased and LTP was increased, irrespective of the stimulation protocol used. In addition, there was clear evidence of increased synaptic excitability in Tg mice. Furthermore, the maximum amplitude of evoked IPSCs was decreased whereas the maximum amplitude of evoked EPSCs was increased in 20-week-old Tg mice. Collectively, these results suggest a number of APP genotype-related changes in the fine-tuning of the CA1 area circuitry, some of which are likely to contribute to the pathology-dependent effects on LTP observed in CRND8 mice. [Copyright &y& Elsevier]

Three polysaccharides, two heteroglycans (PL-1 and PL-4) and one glucan (PL-3), were solubilized from the fruit bodies of Ganoderma lucidum and isolated by anion-exchange and gel-filtration chromatography. Their structural features were elucidated by glycosyl residue and glycosyl linkage composition analyses, partial acid hydrolysis, acetolysis, periodate oxidation, 1D and 2D NMR spectroscopy, and ESI–MS experiments. The data obtained indicated that PL-1 had a backbone consisting of 1,4-linked α-d-glucopyranosyl residues and 1,6-linked β-d-galactopyranosyl residues with branches at O-6 of glucose residues and O-2 of galactose residues, composed of terminal glucose, 1,6-linked glucosyl residues and terminal rhamnose. PL-3 was a highly branched glucan composed of 1,3-linked β-d-glucopyranosyl residues substituted at O-6 with 1,6-linked glucosyl residues. PL-4 was comprised of 1,3-, 1,4-, 1,6-linked β-d-glucopyranosyl residues and 1,6-linked β-d-mannopyranosyl residues. These polysaccharides enhanced the proliferation of T- and B-lymphocytes in vitro to varying contents and PL-1 exhibited an immune-stimulating activity in mice. [Copyright &y& Elsevier]

The general expressions of constitutive equations for isotropic elastic damaged materials were derived directly from the basic law of irreversible thermodynamics. The limitations of the classical damage constitutive equation based on the well-known strain equivalence hypothesis were overcome. The relationships between the two elastic isotropic damage models (i. e. single and double scalar damage models) were revealed. When a single scalar damage variable defined according to the microscopic geometry of a damaged material is used to describle the isotropic damage state, the constitutive equations contain two “damage effect functions”, which describe the different influences of damage on the two independent elastic constants. The classical damage constitutive equation based on the strain equivalence hypothesis is only the first-order approximation of the general expression. It may be unduly simplified and may fail to describe satisfactorily the damage phenomena of practical materials. [ABSTRACT FROM AUTHOR]

The general expressions of constitutive equations for isotropic elastic damaged materials were derived directly from the basic law of irreversible thermodynamics. The limitations of the classical damage constitutive equation based on the well-known strain equivalence hypothesis were overcome. The relationships between the two elastic isotropic damage models (i. e. single and double scalar damage models) were revealed. When a single scalar damage variable defined according to the microscopic geometry of a damaged material is used to describle the isotropic damage state, the constitutive equations contain two “damage effect functions”, which describe the different influences of damage on the two independent elastic constants. The classical damage constitutive equation based on the strain equivalence hypothesis is only the first-order approximation of the general expression. It may be unduly simplified and may fail to describe satisfactorily the damage phenomena of practical materials. [ABSTRACT FROM AUTHOR]

A strategy called targeted gene repair was developed to facilitate the process of gene therapy using a chimeric RNA-DNA oligonucleotide. Experiments demonstrated the feasibility of using the chimeric oligonucleotide to introduce point conversion in genes in vitro and in vivo. However, barriers exist in the low and/or inconstant frequency of gene repair. To overcome this difficulty, three main aspects should be considered. One is designing a more effective structure of the oligonucleotide. Trials have included lengthening the homologous region, displacing the mismatch on the chimeric strand and inventing a novel thioate-modified single-stranded DNA, which was demonstrated to be more active than the primary chimera in cell-free extracts. The second aspect is optimizing the delivery system. Producing synthetic carriers for efficient and specific transfection is demanding, especially for treatment in vivo where targeting is difficult. The third and most important aspect lies in the elucidation of the mechanism of the strategy. Investigation of the mechanism of strand exchange between the oligonucleotide molecule and double-stranded DNA in prokaryotes may greatly help to understand the mechanism of gene repair in eukaryotes. The development of this strategy holds great potential for the treatment of genetic defects and other purposes.Copyright © 2001 National Science Council, ROC and S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Owing to the lack of selection and limited intelligence in mechanical picking, some immature tomatoes that contain alkaloids are thrown away. Tomatine alkaloids are steroidal alkaloids naturally present in Solanaceae plants, which are distributed in small amounts in immature tomato fruits and decrease as the fruits ripen. Tomato glycoalkaloids are harmful to human health. However, in small quantities, there is some evidence that these compounds might be beneficial, as other non-antioxidant bioactivities. This article considers recent research on the biological effects of tomato glycoalkaloids in immature tomatoes, providing reference value for the potential development of these compounds. • Immature tomatoes contain tomatine, which is toxic. • Mechanized harvesting is associated with picking of unripe tomatoes. • Animal studies suggest small amounts of tomatine might reduce risks of some NCDs. • There are examples of tomatine use in food products. [ABSTRACT FROM AUTHOR]

Development of a biotechnological system for rapid degradation of pesticides is important to mitigate the environmental, food security, and health risks that they pose. Degradation of atrazine (ATZ) and isoproturon (IPU) in rice crops promoted by the brassinosteroid (BR) signaling component BRASSINAZOLE RESISTANT4 (OsBZR4) is explored. OsBZR4 is localized in the plasma membrane and nucleus, and is strongly induced by ATZ and IPU exposure. Transgenic rice OsBZR4- overexpression (OE) significantly enhances resistance to ATZ and IPU toxicity, improving growth, and reducing ATZ and IPU accumulation (particularly in grains) in rice crops. Genetic destruction of OsBZR4 (CRISPR/Cas9) increases rice sensitivity and leads to increased accumulation of ATZ and IPU. OE plants promote phase I, II, and III metabolic reactions, and expression of corresponding pesticide degradation genes under ATZ and IPU stress. UPLC-Q-TOF-MS/MS analysis reveals increased relative contents of ATZ and IPU metabolites and conjugates in OE plants, suggesting an increased OsBZR4 expression and consequent detoxification of ATZ and IPU in rice and the environment. The role of OsBZR4 in pesticide degradation is revealed, and its potential application in enhancing plant resistance to pesticides, and facilitating the breakdown of pesticides in rice and the environment, is discussed. [Display omitted] • OsBZR4 positively regulates rice growth and detoxification with ATZ and IPU stress. • OsBZR4 expression decreases ATZ and IPU residues in rice and its environment. • Overexpression of OsBZR4 facilitates the expression of pesticide degradation genes. • Overexpression of OsBZR4 promotes metabolic reactions in rice. • OsBZR4- overexpression plants may reduce ATZ and IPU contamination in rice. [ABSTRACT FROM AUTHOR]

[Display omitted] • N -donor ligands were introduced into open metals sites of MOF by post modification. • Enhanced ideal selectivity for hydrocarbons separation performance were shown in modified frameworks. The separation and purification of light hydrocarbons are performed by energy-intensive distillation processes. Microporous metal–organic framework based absorbents acting as alternative technology gains focus. Open metals sites (OMSs) enriched MOF-74 show great potential in light hydrocarbons but its separation selectivity is low and difficult to regenerate. To address this issue, we introduced N -donor ligands into open sites of Co-MOF-74 by post modification. Structure was determined by powder X-ray diffraction, element analysis, infrared spectroscopy and thermogravimetric analyses. As-synthesized modified Co-MOF-74 display potential in C 2 H 4 /C 2 H 6 , C 3 H 6 /C 3 H 8 , C 3 H 8 /CH 4 and C 2 H 6 /CH 4 separation for N -donor ligands placeholder. [ABSTRACT FROM AUTHOR]

Limited by the cost of electrode materials with a pore structure designed, there is an urgent need to prepare a low-cost carbon material with a strong salt absorption capacity (SAC) for capacitive deionization (CDI) to produce fresh water at an affordable price. The preparation of core-shell porous carbon spheres (CSs) derived from the melamine-formaldehyde (MF) spheres with a urea-citric acid quantum dot (UCQD) layer grown in situ has been reported here. Benefiting from their large specific surface area (2667.44 m2·g−1) and the uniformly doped nitrogen atoms (1.03 at.%), the prepared CSs have abundant active sites for ion absorption. Their SAC reaches up to 19.80 mg·g−1 in the NaCl solution of 1000 mg·L−1 with a working voltage of 1.2 V. Moreover, no SAC attenuation occurs after 17 cycles. This work provides a possible way to prepare low-cost core-shell CSs for CDI. [Display omitted] • Porous CSs with a carbon shell derived from the quantum dots of urea-citric acid grown in situ. • CMF@QD-0.2 exhibit the specific surface area of 2667.44 m2·g-1. • CMF@QD-0.2 have the SAC of 19.80 mg·g-1 in 1000 mg·L-1 NaCl solution at 1.2 V. [ABSTRACT FROM AUTHOR]

Although hepatic metabolism of hexabromocyclododecanes (HBCDs) played critical roles in the selective bioaccumulation of HBCDs in humans, the hepatic metabolism patterns of its enantiomers remained ambiguous. Aiming to elucidate the mechanism on hepatic metabolism of hexabromocyclododecanes (HBCDs) enantiomers, the enantiomers ((+)- α -HBCD, (−)- α -HBCD, (+)- γ -HBCD, and (−)- γ -HBCD), the diastereoisomers (α -, β -, and γ -HBCDs) and the mixed of α - and γ -HBCDs were incubated with human HepG2 cell under different exposure levels in the present study. The clearance percentages ranked as γ -HBCD enantiomers > β -HBCD enantiomers > α -HBCD enantiomers at the same exposure levels. The clearance percentages of (+)- and (−)- α -HBCDs increased when cells were exposed to racemic α -HBCD and the mixture of racemic α - and γ -HBCDs (p < 0.05). (−)- γ -HBCD was more resistant to human hepatic metabolism than (+)- γ -HBCD, leading to the enantiomer fractions (EFs) of γ -HBCD lower than 0.50. (−)- α -HBCD was slightly more metabolized when independently exposed to α -HBCD, while (+)- α -HBCD was more preferentially metabolized after exposure to α - and γ -HBCD mixtures. Hydroxylation and debromination HBCD metabolites were identified. In addition, the different EFs of HBCDs in cells and mediums suggested the selective transfer of chiral HBCDs and HBCD metabolites through the cell membrane. This study provided new insight into the enantiomer-selective metabolism of HBCDs. Unlabelled Image • γ -HBCDs were metabolized more rapidly than α - and β -HBCDs. • Hydroxylated and dibrominated were major HBCDs metabolism pathway in HepG2. • γ -HBCDs exerted enantiomer-dependent antagonistic metabolisms with α -HBCDs in HepG2. • Enantiomer-selective metabolism were predominantly patterns for HBCDs accumulation. • Cellular transfer co-contributed to enantiomer-selective metabolism of HBCDs. [ABSTRACT FROM AUTHOR]

Fe isotopes have been applied to the petrogenesis of ore deposits. However, the behavior of iron isotopes in the mineralization of porphyry-skarn deposits is still poorly understood. In this study, we report the Fe isotopes of ore mineral separations (magnetite, pyrite, chalcopyrite and pyrrhotite) from two different skarn deposits, i.e., the Tonglvshan Cu-Fe skarn deposit developed in an oxidized hydrothermal system and the Anqing Cu skarn deposit developed in a reduced hydrothermal system. In both deposits, the Fe isotopes of calculated equilibrium fluids are lighter than those of the intrusions responsible for the skarn and porphyry mineralization, corroborating the "light-Fe fluid" hypothesis. Interestingly, chalcopyrite in the oxidized-Tonglvshan skarn deposit has lighter Fe than chalcopyrite in the reduced-Anqing skarn deposit, which is best understood as the result of the prior precipitation of magnetite (heavy Fe) from the ore fluid in the oxidized-Tonglvshan systems and the prior precipitation of pyrrhotite (light Fe) from the ore fluid in the reduced-Anqing system. The δ56Fe for pyrite shows an inverse correlation with δ56Fe of magnetite in the Tonglvshan. In both deposits, the Fe isotope fractionation between chalcopyrite and pyrite is offset from the equilibrium line at 350 °C and lies between the FeS-chalcopyrite equilibrium line and pyrite-chalcopyrite equilibrium line at 350 °C. These observations are consistent with the FeS pathway towards pyrite formation. That is, Fe isotopes fractionation during pyrite formation depends on a path from the initial FeS-fluid equilibrium towards the pyrite-fluid equilibrium due to the increasing extent of Fe isotopic exchange with fluids. This finding, together with the data from other deposits, allows us to propose that the pathway effect of pyrite formation in the Porphyry-skarn deposit mineralization is the dominant mechanism that controls Fe isotope characteristics. [ABSTRACT FROM AUTHOR]

Objective To evaluate the application value of laparoscopic anus preserving operation. Methods 240 patients with low rectal cancer were randomly divided into two groups according to the method of operation, 120 patients were treated by laparoscopic in experimental group and the other 120 patients were treated by traditional laparotomy in control group. Then we compared the operation time, hemorrhage during operation, the resuming time of bowel function, anastomotic bleeding, anastomotic fistula and incision infection between the two groups . Results In experimental group, the hemorrhage volume (98.3 ± 43.6) mL was less than control group (286 ± 92) mL (P< 0.05), the resuming time of bowel function (2.3 ± 0.7) d was shorter than control group (3.5 ± 0.9d) (P<0.05), the rate of anastomotic leakage was higher in control group (18 cases) than experimental group (5 cases (P < 0.05) . Conclusion Laparoscopic surgery is feasible, safe, and has less hemorrhage during operation and low incidence of anastomotic fistula for low rectal cancer, it is worthy of clinical popularization and application. [ABSTRACT FROM AUTHOR]

Objective To evaluate the teaching effectiveness of problem-based learning and lecture- based learning in the teaching of surgery operation skill. Methods 120 students in Kunming Medical University were randomly divided into experimental group and control group, each group had 60 students. The teaching effectiveness of the two teaching methods were compared and appraised by examination and questionnaire survey. Results The average score in PBL group was higher than LBL group (P < 0.05), and the satisfaction degree of questionnaire survey in PBL group was higher than LBL group. Conclusion The teaching effectiveness of PBL is better than LBL, the PBL teaching method is worth popularization and application. [ABSTRACT FROM AUTHOR]

A Pd(II)-catalyzed arylation of methylene C(sp³)-H bonds in aliphatic amides directed by our newly developed PIP directing group with aryl iodides/bromides has been achieved. Arylation occurs efficiently with a broad range of aryl halides and amides. [ABSTRACT FROM AUTHOR]

Osteoarthritis (OA) is a chronic joint disorder that causes cartilage degradation and subchondral bone abnormalities. Nangibotide, also known as LR12, is a dodecapeptide with considerable anti-inflammatory properties, but its significance in OA is uncertain. The aim of the study was to determine whether nangibotide could attenuate the progression of OA, and elucidate the underlying mechanism. In vitro experiments showed that nangibotide strongly inhibited TNF-α-induced osteogenic reduction, significantly enhanced osteoblast proliferation and prevented apoptosis in MC3T3-E1 cells. Male C57BL/6 J mice aged 2 months were randomly allocated to three groups: sham, ACLT, and ACLT with nangibotide therapy. Nangibotide suppressed ACLT-induced cartilage degradation and MMP-13 expression. MicroCT analysis revealed that nangibotide attenuated in vivo subchondral bone loss induced by ACLT. Histomorphometry results showed that nangibotide attenuated ACLT-induced osteoblast inhibition; TUNEL assays and immunohistochemical staining of cleaved-caspase3 further confirmed the in vivo anti-apoptotic effect of nangibotide on osteoblasts. Furthermore, we found that nangibotide exerted protective effects by suppressing TGF-β signaling mediated by Smad2/3 to restore coupled bone remodeling in the subchondral bone. In conclusion, the findings suggest that nangibotide might exert a protective effect on the bone-cartilage unit and maybe an alternative treatment option for OA. [ABSTRACT FROM AUTHOR]

Background. This study sets out to investigate the incidence of acute left ventricular failure in peritoneal dialysis patients with different volume loads and to analyze the related risk factors for LVF in these patients. Methods. This study involved patients who received peritoneal dialysis in our hospital between September 2018 and January 2021. The demographic data and biochemical indicators of the patients were collected. The bioimpedance analysis method was used to determine the volume overload [overhydration (OH)] level of patients, and cardiac color Doppler ultrasound was used to detect changes in their cardiac structure. According to the LVF diagnostic criteria of symptoms and laboratory tests, the patients were divided into the LVF and non-LVF groups and then divided according to their OH level into the normal volume (OH ≤1.1 L) and volume overload (OH >1.1 L) groups. The incidence of LVF in was analyzed in patients with different volume loads, and logistic regression was used to identify the risk factors for LVF. Results. Among the 226 peritoneal dialysis patients enrolled in this study, 125 patients (55.3%) had LVF. The normal volume group (n = 68 , 30.1%) included 22 patients (32.4%) with LVF, and the volume overload group (n = 158 , 69.9%) included 84 patients (53.2%) with LVF. In the volume overload group, 74 patients (46.8%) had subclinical volume overload, including 35 patients (47.3%) with LVF, and 84 patients (53.2%) had clinical volume overload, including 65 patients (77.4%) LVF. Multivariate logistic regression analysis revealed a high OH level (OR = 1.862 , 95% CI: 1.353–2.668, P < 0.001) and low hemoglobin level (OR = 0.845 , 95% CI: 0.721–0.980, P = 0.008) to be independent risk factors for LVF. Conclusions. LVF has a high incidence in peritoneal dialysis patients, especially those with volume overload. A high OH level and low hemoglobin level are independent risk factors for LVF. [ABSTRACT FROM AUTHOR]

Addition theory, impedance modulation, nondiffractive beams, orthogonally polarized Bessel beams, tensor holographic metasurface Keywords: addition theory; impedance modulation; nondiffractive beams; orthogonally polarized Bessel beams; tensor holographic metasurface EN addition theory impedance modulation nondiffractive beams orthogonally polarized Bessel beams tensor holographic metasurface 1 1 1 04/07/21 20210401 NES 210401 In article number 2001047, Sanming Hu and co-workers propose a tensor holographic metasurface using addition theory for impedance modulation. Tensor Holographic Metasurfaces: Tensor Holographic Metasurface Using Addition Theory to Independently Manipulate Orthogonally Polarized Bessel Beams (Adv. [Extracted from the article]

The effects of ultraviolet (UV) radiation, particularly UV-B on algae, have become an important issue as human-caused depletion of the protecting ozone layer has been reported. In this study, the effects of different short-term UV-B radiation on the growth, physiology, and metabolism of Porphyra haitanensis were examined. The growth of P. haitanensis decreased, and the bleaching phenomenon occurred in the thalli. The contents of total amino acids, soluble sugar, total protein, and mycosporine-like amino acids (MAAs) increased under different UV-B radiation intensities. The metabolic profiles of P. haitanensis differed between the control and UV-B radiation-treated groups. Most of the differential metabolites in P. haitanensis were significantly upregulated under UV-B exposure. Short-term enhanced UV-B irradiation significantly affected amino acid metabolism, carbohydrate metabolism, glutathione metabolism, and phenylpropane biosynthesis. The contents of phenylalanine, tyrosine, threonine, and serine were increased, suggesting that amino acid metabolism can promote the synthesis of UV-absorbing substances (such as phenols and MAAs) by providing precursor substances. The contents of sucrose, D-glucose-6-phosphate, and beta-D-fructose-6-phosphate were increased, suggesting that carbohydrate metabolism contributes to maintain energy supply for metabolic activity in response to UV-B exposure. Meanwhile, dehydroascorbic acid (DHA) was also significantly upregulated, denoting effective activation of the antioxidant system. To some extent, these results provide metabolic insights into the adaptive response mechanism of P. haitanensis to short-term enhanced UV-B radiation. [ABSTRACT FROM AUTHOR]