Versatile Asymmetric Separator with Dendrite-Free Alloy Anode Enables High-Performance Li-S Batteries.

Lithium-sulfur batteries (LSBs) with extremely-high theoretical energy density (2600 Wh kg-1 ) are deemed to be the most likely energy storage system to be commercialized. However, the polysulfides shuttling and lithium (Li) metal anode failure in LSBs limit its further commercialization. Herein, a versatile asymmetric separator and a Li-rich lithium-magnesium (Li-Mg) alloy anode are applied in LSBs. The asymmetric separator is consisted of lithiated-sulfonated porous organic polymer (SPOP-Li) and Li6.75 La3 Zr1.75 Nb0.25 O12 (LLZNO) layers toward the cathode and anode, respectively. SPOP-Li serves as a polysulfides barrier and Li-ion conductor, while the LLZNO functions as an "ion redistributor". Combining with a stable Li-Mg alloy anode, the symmetric cell achieves 5300 h of Li stripping/plating and the modified LSBs exhibit a long lifespan with an ultralow fading rate of 0.03% per cycle for over 1000 cycles at 5 C. Impressively, even under a high-sulfur-loading (6.1 mg cm-2 ), an area capacity of 4.34 mAh cm-2 after 100 cycles can still be maintained, demonstrating high potential for practical application.

Stable Zinc Anodes Enabled by a Zincophilic Polyanionic Hydrogel Layer.

The practical application of the Zn-metal anode for aqueous batteries is greatly restricted by catastrophic dendrite growth, intricate hydrogen evolution, and parasitic surface passivation. Herein, a polyanionic hydrogel film is introduced as a protective layer on the Zn anode with the assistance of a silane coupling agent (denoted as Zn-SHn). The hydrogel framework with zincophilic -SO3 - functional groups uniformizes the zinc ions flux and transport. Furthermore, such a hydrogel layer chemically bonded on the Zn surface possesses an anti-catalysis effect, which effectively suppresses both the hydrogen evolution reaction and formation of Zn dendrites. As a result, stable and reversible Zn stripping/plating at various currents and capacities is achieved. A full cell by pairing the Zn-SHn anode with a NaV3 O8 ·1.5 H2 O cathode shows a capacity of around 176 mAh g-1 with a retention around 67% over 4000 cycles at 10 A g-1 . This polyanionic hydrogel film protection strategy paves a new way for future Zn-anode design and safe aqueous batteries construction.

Accelerating the activation of Li2MnO3 in Li-rich high-Mn cathodes to improve its electrochemical performance.

Li-rich high-Mn oxides, xLi2MnO3·(1 - x)LiMO2 (x ≥ 0.5, M = Co, Ni, Mn…), have attracted extensive research interest due to their high specific capacity and low cost. However, slow Li2MnO3 activation and poor cycling stability have affected their electrochemical performance. Herein, to solve these problems, morphology regulation and LiAlF4 coating strategies have been synergistically applied to a Li-rich high-Mn material Li1.7Mn0.8Co0.1Ni0.1O2.7 (HM-811). This dual-strategy successfully promotes the activation process of the Li2MnO3 phase and thus improves the electrochemical performance of HM-811. Theoretical computation indicates that the LiAlF4 layer has a lower Li+ migration barrier than the HM-811 matrix, so it could boost the diffusion of Li+ ions and promote the activation of the Li2MnO3 phase. Benefiting from the morphology regulation and LiAlF4 coating, the HM-811 cathode shows a high initial charge capacity of >300 mA h g-1. In addition, the modified HM-811 could deliver superior electrochemical performance even at a low temperature of -20 °C. This work provides a new approach for developing high performance cathode materials for next-generation Li-ion batteries.

Synthesis and anti-gastric cancer activity evaluation of novel triazole nucleobase analogues containing steroidal/coumarin/quinoline moieties.

A series of novel triazole nucleobase analogues containing steroidal/coumarin/quinoline moieties have been synthesized based on copper-catalyzed azide-alkyne cycloaddition (CuAAC). The anti-cancer activity of the new triazole nucleobase analogues was studied in gastric cancer cell lines (MGC-803, SGC-7901) and normal gastric epithelial cells (GES-1) in vitro. Some of the synthesized compounds could significantly inhibit the proliferation of these tested cancer cells. Among the tested compounds, compound 20c demonstrated good anti-proliferation activity against MGC-803 cells (IC50 = 1.48 µM) and SGC-7901 (IC50 = 2.28 µM) cells as well as the best selectivity between the cancer and normal cells. Further mechanistic studies indicated that compound 20c could down-regulate the expression of TGF ß1 both in the tested gastric cancer cell lines and inhibit the cell migration and invasion. The results of the study indicate that compound 20c could be used as a promising skeleton for anti-gastric cancer agents with improved efficacy and less side effects.

Design, synthesis and biological evaluation of new steroidal ß-triazoly enones as potent antiproliferative agents.

ß-Triazoly enones are biologically interesting scaffolds, incorporation of such scaffolds into the steroid nucleus may generate new bioactive steroids and further enrich structural types of steroids. In this work, a series of new steroidal ß-triazoly enones were synthesized based on click chemistry and Claisen-Schmidt condensation reaction and further evaluated for their antiproliferative activity against a panel of cancer cells. Most of these compounds showed better potency against PC-3 and MGC-803 cells. Particularly, compound 5a inhibited PC-3 and MGC-803 cells potently with the IC50 values of 1.61 and 1.16 µM, respectively, and was less toxic toward GES-1 with an IC50 value of 20.72 µM. Further mechanistic studies showed that compound 5a inhibited migration and invasion of MGC-803 and PC-3 dose-dependently. Treatment with compound 5a varied mRNA levels and protein expression of EMT markers in both cells. Collectively, the steroidal ß-triazoly enones could be potentially utilized to develop new anticancer agents with the ability of inhibiting cell migration and invasion.

Protective effect of isoliquiritigenin against cerebral injury in septic mice via attenuation of NF-κB.

BACKGROUND: The study was conducted to scrutinize the outcome of isoliquiritigenin (ISL) against cerebral injury in septic mice. METHODS: The sepsis was introduced using cecal ligation and puncture (CLP) method in experimental mice. The effect of ISL was quantified using the content of brain water and blood brain barrier (BBB) permeability. The effect on the levels of myeloperoxidase (MPO), superoxide dismutase (SOD), malondialdehyde (MDA) and glutathione (GSH) in brain homogenates was also determined. The effect of ISL on the levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1ß, and IL-6 in serum was also estimated. The levels of various inflammatory biomarkers (COX-2 and PGE2) were also studied. The expression of NF-κB signalling cascade and inducible nitric oxide synthase (iNOS) was estimated by Western blot. RESULTS: Compared with CLP group, the brain water content was found to be reduced significantly together with the enhanced BBB integrity in ISL treated group. The level of MDA was reduced together with enhanced level of SOD and GSH in the ISL treated group. The levels of TNF-α, IL-1ß, and IL-6 were also found to be modulated in ISL group. The level of COX-2 and PGE2 was reduced to near normal after ISL administration together with increase in the IκBα expression and reduction of p65 and p-p65 expression in a concentration-dependent manner. The expression of iNOS was also found to be reduced in ISL group. CONCLUSION: These results demonstrate that ISL causes protection of CLP-induced sepsis in experimental mice via multiple pathways.

Effects of spirodiclofen on life history traits and population growth of a spider mite predator Oligota flavicornis (Coleoptera: Staphyllinidae) based on the age-stage two-sex life table theory.

BACKGROUND: Knowledge of the compatibility between spirodiclofen and the predator Oligota flavicornis is an important aspect for the management of spider mites. RESULTS: We used the age-stage, two-sex life table to assess the effects of spirodiclofen on the life history traits and population growth of O. flavicornis. At the maximum recommended concentration (60 mg a.i. L-1 ) and also at twice the maximum recommended dosage (120 mg a.i. L-1 ), the preadult stages of O. flavicornis were significantly lengthened, while the adult longevity and fecundity decreased significantly. The finite rate (λ), intrinsic rate of increase (r), and net reproduction rate (R0 ) decreased, while the mean generation time (T) was longer after both the 60 and 120 mg a.i. L-1 treatments than it was in the control and 30 mg a.i. L-1 treatments. Life expectancy and reproductive value were higher in the control and 30 mg a.i. L-1 treatment than in the 60 and 120 mg a.i. L-1 treatments; the two higher concentrations were detrimental to the development of O. flavicornis. CONCLUSION: A proper combination of the O. flavicornis and spirodiclofen to control the spider mite, while avoiding the side effect of spirodiclofen, could be achieved based on the knowledge of life tables. © 2018 Society of Chemical Industry.

Enantioselective synthesis of enantiopure ß-amino alcohols via kinetic resolution and asymmetric reductive amination by a robust transaminase from Mycobacterium vanbaalenii.

Chiral ß-amino alcohols are very important chiral building block for preparing bioactive compounds for use in pharmaceutical and fine chemical industries. Synthesis of chiral ß-amino alcohols by transaminase is big challenging due to the strict substrate specificities and very low activity of the enzyme. In this work, a (R)-selective ω-transaminase (MVTA) from Mycobacterium vanbaalenii was employed as a biocatalyst for the first time for the synthesis of chiral ß-amino alcohol via kinetic resolution and asymmetric reductive amination. The enzyme was purified and characterized. Kinetic resolution of a set of racemic ß-amino alcohols including two cyclic ß-amino alcohols by MVTA was demonstrated, affording (R)-ß-amino alcohols, (1S, 2S)-trans-2-aminocyclopentanol and (1R, 2S)-cis-1-amino-2-indanols in >99% ee and 50-62% conversion. Asymmetric reductive amination of three α-hydroxy ketones (10-300 mM) by MVTA was conducted, (S)-ß-amino alcohols were obtained with >99% ee and 80-99% conversion. Preparation experiment for the reductive amination of 200 mM 2-hydroxyacetophenone by the resting cells of recombinant E. coli (MVTA) was proceeded smoothly and product (S)-2-amino-2-phenylethanol was obtained with 71% isolated yield, >99% ee and 68.6 g/L/d volumetric productivity. The current research proved that the MVTA is a robust enzyme for the preparation of chiral ß-amino alcohol with high volumetric productivity.

One pot simultaneous preparation of both enantiomer of ß-amino alcohol and vicinal diol via cascade biocatalysis.

OBJECTIVES: To investigate the efficiency of a new cascade biocatalysis system for the conversion of R, S-ß-amino alcohols to enantiopure vicinal diol and ß-amino alcohol. RESULTS: An efficient cascade biocatalysis was achieved by combination of a transaminase, a carbonyl reductase and a cofactor regeneration system. An ee value of > 99% for 2-amino-2-phenylethanol and 1-phenyl-1, 2-ethanediol were simultaneously obtained with 50% conversion from R, S-2-amino-2-phenylethanol. The generality of the cascade biocatalysis was further demonstrated with the whole-cell approaches to convert 10-60 mM R, S-ß-amino alcohol to (R)- and (S)-diol and (R)- and (S)-ß-amino alcohol in 90-99% ee with 50-52% conversion. Preparative biotransformation was demonstrated at a 50 ml scale with mixed recombinant cells to give both (R)- and (S)-2-amino-2-phenylethanol and (R)- and (S)-1-phenyl-1, 2-ethanediol in > 99% ee and 40-42% isolated yield from racemic 2-amino-2-phenylethanol. CONCLUSIONS: This cascade biocatalysis system provides a new practical method for the simultaneous synthesis of optically pure vicinal diol and an ß-amino alcohol.

Temperature-Dependent Development of Oligota flavicornis (Coleoptera: Staphylinidae) Preying on Tetranychus cinnabarinus (Acarina: Tetranychidae).

The effect of nine constant temperatures on developmental time of Oligota flavicornis (Boisduval and Lacordaire) preying on Tetranychus cinnabarinus (Boisduval) (Acari: Tetranychidae) eggs was determined under laboratory conditions of 75 ± 5% RH and a 16:8 (L:D) h photoperiod. O. flavicornis survival rates were highest between 18 and 30°C, although O. flavicornis eggs developed successfully to adults at 12-32°C, and the developmental durations to adult at the seven temperatures (12, 15, 18, 20, 25, 30, and 32°C) were 114.41, 51.66, 33.45, 23.21, 13.43, 11.54, and 17.18 d, respectively. Two linear and seven nonlinear models (Logan-6 and Logan-10, Taylor, Lactin-1 and Lactin-2, and Brière-1 and Brière-2) were fit to the developmental rates of the immature predatory stages to estimate the thermal constant (K) and critical temperatures. The lower temperature threshold (T0) and K for the immature stages using the common linear model were 9.96°C and 225.73 degree-days and Ikemoto-Takai linear model were 11.01°C and 167.14 degree-days, respectively. The upper temperature threshold values estimated by the Logan-6 and Lactin-1 models were both 34.86°C. The T0 values estimated by the Brière-1 and Brière-2 models were 10.67 and 9.32°C for all immature stages, respectively, and the estimated optimal temperature according to the Brière-2 model was 29.59°C. Therefore, the two linear models and Brière-2 model estimates approximated the actual relationship between the temperature and developmental rate of immature O. flavicornis.

Dynamics of Bemisia tabaci biotypes and insecticide resistance in Fujian province in China during 2005-2014.

The whitefly Bemisia tabaci (Gennadius) is an important agricultural insect pest worldwide. The B and Q biotypes are the two most predominant and devastating biotypes prevalent across China. However, there are few studies regarding the occurrence of the Q biotype in Fujian Province, China, where high insecticide resistance has been reported in the B biotype. Differences in some biological characteristics between the B and Q biotypes, especially insecticide resistance, are considered to affect the outcome of their competition. Extensive surveys in Fujian revealed that the B biotype was predominant during 2005-2014, whereas the Q biotype was first detected in some locations in 2013 and widely detected throughout the province in 2014. Resistance to neonicotinoids (that have been used for more than 10 years) exhibited fluctuations in open fields, but showed a continual increasing trend in protected areas. Resistance to lambda-cyhalothrin, chlorpyrifos, and abamectin exhibited a declining trend. Resistance to novel insecticides, such as nitenpyram, pymetrozine, sulfoxaflor, and cyantraniliprole, in 2014 was generally below a moderate level. A decline in insecticide resistance in the B biotype and the rapid buildup of protected crops under global temperature increase may have promoted the establishment of the Q biotype in Fujian.

[Pollution Characteristics of Surface Runoff of Typical Town in Chongqing City].

Six kinds of impermeable underlying surface, cement tile roof, asbestos roof, cement flat roof, residential concrete pavement, asphalt pavement of restaurants, asphalt pavement of oil depot, and a combined sewer overflow canal in the Jiansheng town of Dadukou district in Chongqing city were chosen as sample plots to study the characteristics of nutritional pollutants and heavy metals in town runoff. The research showed that the average mass concentrations of TSS, COD, TN, TP in road runoff were (1681.2 +/- 677.2), (1154.7 +/- 415.5), (12.07 +/- 2.72), (3.32 +/- 1.15) mgL(-1), respectively. These pollutants were higher than those in roof runoff which were (13.3 +/- 6.5), (100.4 +/- 24.8), (3.58 +/- 0.70), (0.10 +/- 0.02) mg x L(-1), respectively. TDN accounted for 62.60% +/- 34.38% of TN, and TDP accounted for 42.22% +/- 33.94% of TP in the runoff of impermeable underlying surface. Compared with the central urban runoff, town runoff in our study had higher mass concentrations of these pollutants. The mass concentrations of TSS, COD, TDN, TN, TDP and TP in the combined sewer overflow were (281.57 +/- 308.38), (231.21 +/- 42.95), (8.16 +/- 2.78), (10.60 +/- 3.94), (0.38 +/- 0.23) and (1.51 +/- 0.75) mg x L(-1), respectively. The average levels of heavy metals in this kind of runoff did not exceed the class VI level of the surface water environmental quality standard. Most pollutants in the combined sewer overflow had first flush. However, this phenomenon was very rare for TSS. There was a significant positive correlation between TSS and COD, TP in the combined sewer overflow. And this correlation was significant between NH4+ -N and TP, TDP, TN, TDP. However, a negative correlation existed between NO3- -N and all other indicators.

Lethal and sublethal effects of thiamethoxam on the whitefly predator Serangium japonicum (Coleoptera: Coccinellidae) through different exposure routes.

Given expectations for a booming usage of thiamethoxam and increasing availability of the promising biological agent Serangium japonicum for the control of Bemisia tabaci in China, an evaluation of their compatibility is crucial for integrated pest management (IPM). This study examined the lethal and sublethal effects of thiamethoxam on S. japonicum through three exposure routes. An acute toxicity bioassay showed that LC50 values of thiamethoxam for S. japonicum through residue contact, egg-dip, and systemic treatment were 6.65, 4.37, and 2.43 mg AI L(-1), respectively. The prey consumption of S. japonicum given different densities of B. tabaci eggs under control, discontinuous, egg-dip and systemic exposure scenarios showed a good fit to a Type II functional response. Predation of S. japonicum was most affected under systemic exposure, followed by egg-dip, and discontinuous, which was only slightly affected. In all cases tested, however, predators recovered their predation capacity rapidly, either after 24h of exposure or 24h after the end of exposure. Thiamethoxam was highly toxic to S. japonicum regardless of exposure routes. Sublethal effects of thiamethoxam applied systemically or foliar both impaired the biological control of S. japonicum on B. tabaci. Therefore, thiamethoxam should be used with caution in IPM of B. tabaci.

[Research on stormwater runoff quality of mountain city by source area monitoring].

Stormwater runoff samples were collected from 10 source areas in Mountain City, Chongqing, during five rain events in an attempt to investigate the characteristics of runoff quality and influencing factors. The outcomes are expected to offer practical guidance of sources control of urban runoff pollution. The results indicated that the stormwater runoff of Mountain City presented a strong first flush for almost all events and constituents. The runoff quality indices were also influenced by the rainfall intensity. The concentration of TSS, COD, TN and TP decreased as the rainfall intensity increased. The concentrations of COD and TP in stormwater runoff were highly correlated with TSS concentrations. Suspended solid matter were not only the main pollutant of stormwater runoff but also served as the vehicle for transport of organic matter and phosphorus. Organic matter and phosphorus in stormwatrer runoff were mainly bound to particles, whereas nitrogen was predominantly dissolved, with ammonia and nitrate. A significant difference of stormwater runoff quality was observed among the ten monitored source areas. The highest magnitude of urban stormwater runoff pollution was expected in the commercial area and the first trunk road, followed by the minor road, residential area, parking lot and roof. Urban surface function, traffic volume, population density, and street sweeping practice are the main factors determining spatial differentiation of urban surface runoff quality. Commercial area, the first trunk road and residential area with high population density are the critical sources areas of urban stormwater runoff pollution.

[Response of phosphorus components in sediments from eutrophic lake to external sulfate].

A six week experiment under indoor simulated condition was carried out to investigate the external sulfate transformation between the sediments and overlying water from Lake Nanhu in Wuhan, China, and the influence of sulfate on the phosphorus components was also studied. The results showed that the sulfate input increased the pH and lowered the Eh in the overlying water. The sulfate concentration in the overlying water decreased with time, and it was assumed that there existed an obvious transformation of sulfate to other forms of sulfur compounds according to the variation of sulfate concentration in the pore water. The sulfate reduction index increased with higher input content of sulfate. The amount of sulfate reducing bacteria (SRB) in the sediments achieved the peak value in the second week, and the SRB amounts of S500 and S1000 were much higher than that of the control. 31P-NMR was used to characterize the relative quantity of phosphorus compounds in the sediment extracts leached by NaOH-EDTA. The components of phosphorus in Nanhu Lake sediment were mainly orthophosphate, phosphate monoester, phosphodiester and pyrophosphate. The predominant one was orthophosphate (84.10%-95.54% of total phosphorus). The contents of other phosphorus components were followed: phosphate monoester > phosphodiester > pyrophosphate, and they increased due to the input of sulfate during the first four weeks, and decreased in the last two weeks. The external sulfate accelerated the release of orthophosphate from sediments to overlying water in a whole, and increased the contents of phosphate monoester, phosphodiester and pyrophosphate in sediments when the amounts of sulfate reducing bacteria were high.

Antihypertensive effects of olmesartan compared with other angiotensin receptor blockers: a meta-analysis.

OBJECTIVES: Angiotensin II type 1 receptor antagonists (angiotensin receptor blockers [ARBs]) have been shown to be effective and well tolerated in hypertensive patients. Olmesartan is the seventh angiotensin receptor blocker licensed by the US Food and Drug Administration. The aim of this meta-analysis was to determine the efficacy and tolerability of olmesartan medoxomil in comparison with other ARBs. DATA SOURCES: Reports of randomized controlled trials (RCTs) of olmesartan versus other ARBs were identified through a systematic search of PubMed (up to July 2010), EMBASE (1980 to July 2010), SinoMed (up to July 2010), and the Cochrane Central Register of Controlled Trials (Cochrane Library Issue 7, 2010). REVIEW METHODS: Pertinent studies were selected through extensive searches of PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and SinoMed. Two of the authors abstracted data from the identified studies independently. Criteria for inclusion in our meta-analyses were randomized clinical trials in which patients were receiving an ARB and outcome data for blood pressure reduction or the incidence of adverse events were available. Quantitative and qualitative analyses of data from all RCTs meeting the criteria were performed. Our meta-analysis was undertaken according to the Quality of Reporting Meta-analyses (QUOROM) statement. RESULTS: Twenty-two studies with data from 4892 patients were considered for analyses. Olmesartan provided greater diastolic blood pressure (DBP) and systolic blood pressure (SBP) reductions compared with losartan (DBP: 95% confidence interval [CI] 0.59, 2.62; SBP: 95% CI 0.46, 5.92). Olmesartan provided greater SBP reductions compared with valsartan (95% CI 0.29, 3.16). Similar blood pressure response rates and incidence of adverse events were found with losartan, valsartan, candesartan, and irbesartan. CONCLUSION: Olmesartan provides better antihypertensive efficacy than losartan and valsartan and has no association with an increased risk of adverse events in comparison with losartan, valsartan, candesartan, and irbesartan.

[Biological activity of capsaicin and its effects on development and fecundity in Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae)].

Biological activity of capsaicin and its effects on development and fecundity in Bemisia tabaci were tested in the laboratory. The results showed that capsaicin induced direct mortality in different developmental stages of B. tabaci, and the mortality of whiteflies were significantly dosage-dependent. The toxicity of capsaicin to different developmental stages of B. tabaci by either leaf-dip or egg/larval-dip bioassays (the LC50 for adult, egg and nymph were 3525.79, 1603.29 and 1526.27 mg x L(-1), respectively) was higher than that by systemic bioassay (the LC50 for adult, egg and nymph were 5360.04, 2359.19 and 5897.43 mg x L(-1), respectively), and toxicity of capsaicin to eggs was higher than to adults in both bioassay methods. 2000 and 4000 mg x L(-1) concentrations of capsaicin had strong antifeedant effect on B. tabaci, as exemplified by reduced honeydew excretion of adults feeding on leaves treated with capsaicin compared with untreated leaf discs. Capsaicin also had strong oviposition deterrence against B. tabaci, with 94. 2% of selective oviposition deterrence rate and 83. 0% of nonselective oviposition deterrence rate when exposed to 4000 mg x L(-1) concentration for 24 h. We did not find effect on development time of B. tabaci eggs and nymphs, and on molting rate of adults when exposed to capsaicin at 500, 1000 and 2000 mg x L(-1) concentrations, however, exposure to 4000 mg x L(-1) concentration of capsaicin significantly affected development time of B. tabaci nymphs and molting rate of adults. Exposure to capsaicin also significantly reduced fecundity of B. tabaci adults, and this reduction was significantly dosage-dependent.

[Development of insecticide resistance and its effect factors in field population of Bemisia tabaci in Fujian Province, East China].

Abstract: The development of insecticide resistance in field populations of Bemisia tabaci from different regions of Fujian Province, China were monitored with adult leaf-dipping bioassay. Compared with bioassay data of 2005, all field populations tested in 2009 still had high levels of resistance to the lambda-cyhalothrin, fenpropathrin and chlorpyrifos, low levels of resistance to methomyl, and no resistance to abamectin. However, resistance to the neonicotinoids imidacloprid and thiamethoxam had increased from moderate levels (23 folds and 25 folds, respectively) in 2005 to high levels (103 folds and 228 folds, respectively) in 2009 in Zhangzhou population, and low levels (1.5-3.3 folds and 1.7-5.5 folds, respectively) in 2005 to moderate levels (23-33 folds and 29-49 folds, respectively) in 2009 for other populations. The biotype of eight B. tabaci populations collected from different regions and hosts were determined according to the mitochondria cytochrome oxidase I (mtCO I ) sequence, and two different biotypes (B-biotype and indigenous whitefly) were detected. The samples collected from geographical regions and hosts showed a prevalence of the B-biotype, and indigenous whitefly (unknown biotype) existed only in croton of Zhangzhou. Host plants and temperature had limited effects on insecticide development in B. tabaci, while extensive and high frequent use of neonicotinoids could be the most important factors responsible for rapid development of insecticide resistance in field populations of B-biotype B. tabaci.

Synthesis of a novel series of diphenolic chromone derivatives as inhibitors of NO production in LPS-activated RAW264.7 macrophages.

A novel series of diphenolic chromone derivatives were synthesized and their inhibitory activity on nitric oxide (NO) production and cytotoxicity were evaluated using LPS-activated murine macrophages RAW264.7 assay and MTT method, respectively. Among these compounds, (5,7-dihydroxy-4-oxo-4H-chromen-3-yl) methyl esters (6b, 6c, 6f, 6g, and 6h) showed quite potent inhibitory activities with IC(50) values of 2.20, 3.48, 0.35, 0.80, and 0.61microM, respectively. The MTT results showed that all of the active compounds exhibited no cytotoxicity at the effective concentrations. The preliminary mechanism of the most potent compounds (6b, 6c, 6f, 6g, and 6h) was further examined based on the RT-PCR results and the compounds 6f, 6g, and 6h inhibited NO production by suppressing the expression of iNOS mRNA in a dose dependent manner. Furthermore, a computational analysis of physicochemical parameters revealed that the most of the compounds possessed drug-like properties.