Search

The Asian corn borer (ACB), Ostrinia furnacalis, (Lepidoptera: Crambidae), a significant threat to corn crops, necessitates comprehensive research on its populations, across multiple clades. This study addresses the efficacy of various diets, such as an antibiotic mixed diet of amoxicillin mixed with artificial diet, wheat germ flour artificial diet and fresh corn leaves, for the successful mass rearing of three clades of O. furnacalis, and investigates variations among the insects reared under laboratory conditions. We validate these findings for O. furnacalis clades using biological attributes. Notably, clade III demonstrated enhanced biological characteristics with an antibiotic mixed diet, in contrast to clades I and II, with higher growth indexes observed during mass rearing. Through revealing a suitable diet for the clade, this research advances our understanding of O. furnacalis dynamics and offers valuable insights for practical applications in an integrated pest management program. [ABSTRACT FROM AUTHOR]

Photothermal therapy is a new, promising approach for treating cancer in a noninvasive way. Herein, a photothermally efficient nanomaterial is synthesized by exposing bulk WS2 powder, dispersed in carbon‐rich acetonitrile, to high‐intensity femtosecond laser pulses. The photothermal measurements show a significantly higher rise in temperature and enhance photothermal efficiency for the laser‐treated material. The attribution is on the enhancement to the formation of tungsten semi‐carbide (W2C), which is verified by morphological and structural characterization. The tungsten semi‐carbide is formed by laser‐induced carburization; intense laser pulses knock S atoms out of the WS2 lattice and dissociate the acetonitrile molecules, resulting in the formation of W2C. Interestingly, the hexagonal W2C has a two‐dimensional (2D) layered morphology like that of the WS2, suggesting its morphology is not random and might be determined by the morphology of the parent material. The study provides a simple route to transform a 2D transition‐metal dichalcogenide into a 2D transition‐metal carbide, which is useful for applications including photothermal therapy. [ABSTRACT FROM AUTHOR]

BACKGROUND: The rice moth, Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae) is a pest of stored grains and widely used as a factitious host during the mass rearing of several natural enemies of crop pests. Hormesis is well‐documented in pest insects, to some extent in natural enemies of pests. RESULTS: We report transgenerational stimulatory effects of the widely used fumigant, phosphine. The study reports the consequences of sublethal, low lethal and median lethal concentrations (LC5, LC25 and LC50) and untreated control for two sequential generations of the species (G1 to G2). In this study, we investigated the life‐history traits, nutrient reserves (protein, lipid and carbohydrate) and larval gut microbiome (using 16 s rRNA V3–V4 metagenomics sequencing) of C. cephalonica. Stimulatory effects were observed for various biological traits of C. cephalonica, notably adult longevity, emergence and increased egg hatchability when exposed to LC5 of phosphine. The total protein, lipid and carbohydrate contents of C. cephalonica also were found to be significantly increased by LC5 in both generations. The microbial diversity of LC5 treated larval gut was higher and found to be different from the rest of the treatments. This is the first report showing hormesis to a fumigant insecticide. CONCLUSION: Our findings increase knowledge on the interaction between hormesis, nutrient reserves and gut bacteria in C. cephalonica exposed to insecticides. Overall, the present study establishes phosphine‐induced hormesis at LC5 in the host C. cephalonica, which might help improve the quality of mass rearing of various natural enemies. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Myzus persicae (Sulzer) is a globally distributed crop pest with a wide host range. The L1014F mutation in the voltage‐gated sodium channel has been implicated in mediating resistance to pyrethroid insecticides in M. persicae. Control failures in crop production are frequently attributed to inaccurate or delayed detection of M. persicae resistance. Thus, simple and effective tools for detecting resistant M. persicae are required to develop rapid and flexible pest control strategies. The resistance assay and L1014F mutation frequency assay results showed that the L1014F mutation frequency could infer M. persicae's resistance level to pyrethroid insecticides. Therefore, in our study, we established a Loop‐Mediated Isothermal Amplification (LAMP)‐based method to detect the L1014F mutation in the voltage‐gated sodium channel of M. persicae. This method uses single aphid crude extract DNA as a template, and the full reaction can be completed in 1 h in a relaxed temperature range. The results could also be obtained by colour change without any molecular detection. We have also optimized the reaction system and procedures to improve the accuracy of the assay to over 95%. Based on this, we can detect the mutation frequency of voltage‐gated sodium channel L014F in M. persicae field populations in a non‐laboratory setting, such as in the field, in a stable, accurate, and rapid manner. This method facilitates quick determination of the resistance of M. persicae populations, followed by guide field control. [ABSTRACT FROM AUTHOR]

BACKGROUND: Drosophila suzukii (Matsumura) is considered a quarantine pest in the A2 list because it causes serious infection and huge economic losses. Cold and controlled atmosphere treatments have been used to control immature stage pests in fresh fruits. Herein, the basal tolerance response of D. suzukii egg, larva and pupa to cold and hypoxia stress were studied, and underlying transcriptome mechanisms in the larva were pinpointed. RESULTS: The third instar was more tolerant than 12‐h‐old egg and 8‐day‐old pupa when treated at 3 °C + 1% O2 for 7 days, with 34.00% ± 5.22% larval survival. Hypoxia influenced the effect of cold treatment on D. suzukii. Larval survival decreased at 3 °C + 1% O2, but increased at 0 °C + 1% O2. Survival increased with temperature between 0 and 5 °C + 1% O2, but decreased significantly at 25 °C + 1% O2. RNA‐sequencing results showed that the Tweedle (Twdl) family was upregulated and uniquely enriched in larvae treated at 3 °C + 1% O2. In addition, RNA interference‐mediated silencing of a key Twdl gene reduced the survival rate after cold and hypoxia treatment. CONCLUSION: Hypoxia was able to influence the effect of cold treatment on the survival of D. suzukii positively or negatively. Structural constituents of the chitin‐based cuticle, in particular Twdl genes, body morphogenesis, and ATP synthesis‐coupled proton transport were involved in the tolerance to cold and hypoxia. In future, the Twdl gene could be used as a nanocarrier delivering RNA pesticides to control D. suzukii in the field and so prevent its worldwide spread. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Background and Aims: Health care workers (HCWs) are thought to be high‐risk population for acquiring coronavirus disease (COVID‐19). The COVID‐19 emergence has had a profound effect on healthcare system. We sought to investigate the COVID‐19 among HCWs and their effects on the healthcare system. Methods: A cross sectional observational study was conducted at Timergara teaching hospital. The study included HCWs with positive real time polymerase chain reaction (Q‐PCR) for severe acute respiratory syndrome coronavirus (SARS‐CoV‐2). The study duration was from April to September, 2020. The demographic profile of each recruited subject was collected through structured interview. The patient's admissions to hospital were collected for the 5 months before (October 2019–February 2020) and 5 months after lockdown (March–July 2020). Results: A total of 72 out of 689 (10%) HCWs were tested positive for SARS‐CoV‐2, of whom 83% were front‐liners. The majority were male (72%), with comorbidities (14%) and no mortality. The structured interview of all participants showed that the healthcare setting was the major possible source of infection (97%). The patient admissions into the hospital were reduced by 42% during lockdown than prelockdown period. The patients admission was significantly decreased in the medical ward during lockdown (60% decrease; p < 0.01) with slightly similar trends in other departments. Conclusion: In conclusion, we found increased risk of COVID‐19 for front‐line HCWs. Lack of mortality was the favorable outcome. Lack of replacing the infected HCWs possibly explained the marked decrease in hospital admissions, and potential inadequate healthcare delivery during the lockdown. Understanding SARS‐CoV‐2 among HCWs and their impact on health‐care system will be crucial for countries under COVID‐19 crises or in case of future pandemic to deliver proper health services. [ABSTRACT FROM AUTHOR]

BACKGROUND: The peach‐potato aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae), is a major pest worldwide. The intensive use of insecticides has led to the development of resistance against neonicotinoid insecticides. The R81T mutation in the nicotinic acetylcholine receptor (nAChR) beta1 subunit is considered a crucial mechanism adaptation to neonicotinoid resistance in M. persicae and Aphis gossypii. RESULTS: Resistance‐related mutations (R81T and V101I) were detected in the imidacloprid‐resistant M. persicae AH19 population. The V101I mutation is reported for the first time. The V101I and R81T mutations existed separately, indicating that the two mutations evolved independently. Imidacloprid resistance in the AH19 population was stable without insecticide exposure. Four mutant strains were selected from the population with stable resistance. The resistance of the AH19‐T, AH19‐I, and AH19‐TI strains to imidacloprid, thiamethoxam, and dinotefuran was significantly increased compared with the AH19‐W strain. Synergism bioassays showed that the inhibition of three detoxification enzymes did not affect imidacloprid resistance in the AH19‐T and AH19‐I strains. Expression of nAChR β1 subunits in the AH19‐W, AH19‐T, and AH19‐I strains remained unchanged. CONCLUSION: The V101I mutation is associated with neonicotinoid resistance in M. persicae. The resistance of the AH19‐T and AH19‐I strains to neonicotinoids appears to be mainly due to the R81T and V101I mutations, whereas these mutations, together with changes in the cytochrome P450 monooxygenases and nAChR expression may be responsible for the development of neonicotinoid resistance in the AH19‐TI strain. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

BACKGROUND: In insects, carboxylesterases (CarEs) are enzymes involved in the detoxification of insecticides. However, the molecular mechanism of CarE‐mediated insecticide metabolism in Bradysia odoriphaga, a serious agricultural pest, remains unclear. The aim of this study is to investigate the detoxification process of malathion, bifenthrin, and imidacloprid by B. odoriphaga carboxylesterase (Boest1). RESULTS: An alpha class CarE gene Boest1 was cloned from B. odoriphaga. The results of real‐time quantitative polymerase chain reaction showed that Boest1 is up‐regulated with age during the larval stage, and the level of transcription of Boest1 is higher in the midgut and Malpighian tubule than in other tissues. The expression level of Boest1 was significantly increased after exposure to malathion and bifenthrin. Recombinant BoEST1 expressed in vitro showed high catalytic activity toward α‐naphthyl acetate, which was substantially inhibited by malathion and triphenyl phosphate. The in vitro metabolism assays showed that BoEST1 demonstrates hydrolytic capacity toward malathion and bifenthrin but not imidacloprid. The binding free energy analysis indicates that BoEST1 has a higher affinity for malathion and bifenthrin than imidacloprid. CONCLUSION: These results suggest that BoEST1 plays a role in the breakdown of insecticides and may be involved in the development of resistance in the Chinese chive pest B. odoriphaga; our findings also provide data for better pest management and perspectives for new pesticides development. © 2021 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The spotted wing drosophila, Drosophila suzukii Matsumura (Diptera: Drosophilidae), distributes in most soft‐skinned fruit areas in China, is an economically important pest of fresh cherries during Sino‐European trade and is considered a quarantine pest in A2 list by European and Mediterranean Plant Protection Organization. Loop‐mediated isothermal amplification (LAMP) is an accurate, quick and convenient molecular identification method, applied to distinguish D. suzukii from other fruit flies. This method can be used for inspection in the field, and at the points of entry (POEs), because its results can be detected with the naked eye due to colour changes. In our study, first, we reported a simple and fast LAMP colorimetric detection method for molecular identification of D. suzukii. We designed primer sets for D. suzukii based on mitochondrial cytochrome oxidase I (COI) sequences. The specificity and sensitivity of the primers were tested by using target and non‐target fruit flies in the family Drosophilidae and Tephritidae, usually intercepted during the Sino‐European cherry trade. Second, for detection in the field and at POEs, the adoption of a quick DNA extraction method could save the total time of LAMP identification to about 90 min. Taken together, this accurate, quick and convenient LAMP‐based colorimetric identification assay combined with a quick DNA extraction method could visually detect clearly with just one portable heating device, which will be useful for rapid on‐site identification and inspection for D. suzukii by the quarantine department. [ABSTRACT FROM AUTHOR]

Two novel mononuclear copper (II) complex catalysts were synthesized from a new tridentate iminoisonicotine ligand (HL) by coordination with Cu(II) ion, with (CuL@TiO2@Fe3O4) and without (CuL) immobilization on TiO2‐coated nanoparticles of Fe3O4. The ester moiety on the back of the ligand was utilized for immobilization on nanoparticles of Fe3O4. Both ligand and CuL complex were fully characterized by using alternative spectral techniques (nuclear magnetic resonance, infrared, ultraviolet‐visible and mass spectroscopy, and elemental analyses). Different analytical techniques were used to identify the structural feature and morphology of the immobilized copper catalyst (CuL@TiO2@Fe3O4) shell‐shell‐core system. The structural analysis revealed that the catalyst system is composed of both agglomerated nanospheres and deformed nanorods. Both copper catalysts, immobilized CuL@TiO2@Fe3O4 and un‐immobilized CuL were studied in heterogeneous and homogeneous catalysis, respectively, for Suzuki‐Miyaura (C–C) and Buchwald‐Hartwig (C–N) cross‐coupling reactions of various heteroaryl halides. Both catalysts showed good catalytic potential under the controlled optimal reaction conditions. In contrast to the homogeneous catalyst (CuL), the heterogeneous catalyst (CuL@TiO2@Fe3O4) showed slightly better catalytic performance. The characteristic obtains supported the catalytic potential of the current samples. Reusability/recycling of both catalysts was also investigated in C–C cross‐coupling reactions. It was found that the homogeneous catalyst (CuL) could be only recycled up to three times, whereas the heterogeneous one (CuL@TiO2@Fe3O4) could be reused up to seven times with good efficiency. [ABSTRACT FROM AUTHOR]

The atomic or molecular assembly on 2D materials through the relatively weak van der Waals interaction is quite different from the conventional heteroepitaxy and may result in unique growth behaviors. Here, it is shown that straight 1D cyanide chains display universal epitaxy on hexagonal 2D materials. A universal oriented assembly of cyanide crystals (AgCN, AuCN, and Cu0.5Au0.5CN) is observed, where the chains are aligned along the three zigzag lattice directions of various 2D hexagonal crystals (graphene, h‐BN, WS2, MoS2, WSe2, MoSe2, and MoTe2). The potential energy landscape of the hexagonal lattice induces this preferred alignment of 1D chains along the zigzag lattice directions, regardless of the lattice parameter and surface elements as demonstrated by first‐principles calculations and parameterized surface potential calculations. Furthermore, the oriented microwires can serve as crystal orientation markers, and stacking‐angle‐controlled vertical 2D heterostructures are successfully fabricated by using them as markers. The oriented van der Waals epitaxy can be generalized to any hexagonal 2D crystals and will serve as a unique growth process to form crystals with orientations along the zigzag directions by epitaxy. [ABSTRACT FROM AUTHOR]

Oculocutaneous albinism (OCA) is an autosomal‐recessive disorder of a defective melanin pathway. The condition is characterized by hypopigmentation of hair, dermis, and ocular tissue. Genetic studies have reported seven nonsyndromic OCA genes, among which Pakistani OCA families mostly segregate TYR and OCA2 gene mutations. Here in the present study, we investigate the genetic factors of eight consanguineous OCA families from Pakistan. Genetic analysis was performed through single‐nucleotide polymorphism (SNP) genotyping (for homozygosity mapping), whole exome sequencing (for mutation identification), Sanger sequencing (for validation and segregation analysis), and quantitative PCR (qPCR) (for copy number variant [CNV] validation). Genetic mapping in one family identified a novel homozygous deletion mutation of the entire TYRP1 gene, and a novel deletion of exon 19 in the OCA2 gene in two apparently unrelated families. In three further families, we identified homozygous mutations in TYR (NM_000372.4:c.1424G > A; p.Trp475*), NM_000372.4:c.895C > T; p.Arg299Cys), and SLC45A2 (NM_016180:c.1532C > T; p.Ala511Val). For the remaining two families, G and H, compound heterozygous TYR variants NM_000372.4:c.1037‐7T > A, NM_000372.4:c.1255G > A (p.Gly419Arg), and NM_000372.4:c.1255G > A (p.Gly419Arg) and novel variant NM_000372.4:c.248T > G; (p.Val83Gly), respectively, were found. Our study further extends the evidence of TYR and OCA2 as genetic mutation hot spots in Pakistani families. Genetic screening of additional OCA cases may also contribute toward the development of Pakistani specific molecular diagnostic tests, genetic counseling, and personalized healthcare. [ABSTRACT FROM AUTHOR]

In this study, we utilized picosecond pulses from an Nd:YAG laser to investigate the nonlinear optical characteristics of monolayer MoSe2. Two-step growth involving the selenization of pulsed-laser-deposited MoO3 film was employed to yield the MoSe2 monolayer on a SiO2/Si substrate. Raman scattering, photoluminescence (PL) spectroscopy, and atomic force microscopy verified the high optical quality of the monolayer. The second-order susceptibility χ(2) was calculated to be ∼50 pm V−1 at the second harmonic wavelength [ABSTRACT FROM AUTHOR]

During the course of screening of medicinal plants of Pakistan for the isolation and structure elucidation of bioactive natural products, it was found that the methanol extract of the Rhododendron collettianum showed analgesic and spasmolytic activities. The methanol extract was then extracted with chloroform. Nine pentacyclic triterpenes were isolated from the chloroform extract and their structures were elucidated as erythrodiol (1), betulinic acid (2), maslinic acid (3), 2 α,3 α,23-trihydroxyolean-12-en-28-oic acid (4), bayogenin (5), arjunilic acid (6), methyl arjunolate (7), arjungenin (8) and 3 β, 23, 24-trihydroxyolean-12-en-28-oic acid (9). Among the triterpenes (1-9) tested, arjunilic acid (6) was found to be most potent. Their structure-activity relationship (SAR) showed that if the configuration of the -OH group at C-2 is changed from α to β the potency is decreased. In most of the compounds the position and configuration of the -OH group was found to be important for the inhibitory potency against the enzyme tyrosinase. For the comparison, the standard tyrosinase inhibitors kojic acid (IC50 = 16.67 µ m) and l-mimosine (IC50 = 3.68 µ m) were used as controls. Copyright © 2007 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The crude extract of Carthamus oxycantha (Co.Cr) and its fractions were studied in vitro for their possible spasmogenic and spasmolytic activities. Co.Cr (0.03-10 mg/mL) caused an atropine sensitive spasmogenic effect in guinea-pig ileum. In spontaneously contracting rabbit jejunum preparations, Co.Cr caused a dose-dependent (0.03-3.0 mg/mL) spasmogenic effect, followed by relaxation at the next higher doses of 5.0-10.0 mg/mL. In the presence of atropine, the spasmogenic effect was blocked and the relaxant effect was observed at lower doses (0.1-5.0 mg/mL), shifting the inhibitory dose-response curves to the left. Co.Cr also inhibited K+ (80 m m)-induced contractions in atropinized preparations at similar doses, suggesting calcium channel blockade (CCB) activity. The CCB effect was further confirmed when pretreatment of the tissue with Co.Cr produced a dose-dependent shift in the Ca++ dose-response curves to the right, similar to that caused by verapamil. Activity-directed fractionation revealed that the spasmolytic effect was concentrated in organic fractions in the following order of potency: hexane > ethylacetate > chloroform, while the aqueous fraction exhibited spasmogenic and weak spasmolytic effects. These results indicate that Carthamus oxycantha contains a combination of spasmogenic (cholinergic) and spasmolytic (calcium antagonist) constituents. Copyright © 2005 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Background: Syndactyly is a clinical feature of split‐hand foot malformation (SHFM), ectodermal‐dysplasia‐syndactyly (EDSS1) and Cenani–Lenz syndactyly syndromes (CLSS). In EDSS1, only cutaneous syndactyly is observed, with sparse hair, abnormal nails and dentition. In SHFM, bony syndactyly may vary from hypoplasia of one phalanx to aplasia of central digits, extending to complete fusion of all fingers and toes in CLSS. Several genes have been assigned to these syndromes. Performing a single step molecular diagnostics becomes a challenge when a phenotype has overlaps with several syndromes or when some of the clinical features are not fully expressed in patients. Methods: Whole exome sequencing (WES) analysis on one sample derived from a consanguineous family was performed. A causative variant in WES data was prioritized via standard bioinformatics tools. The selected variant was Sanger sequenced in all the available family members for autosomal recessive segregation. Results: A novel missense variant (c.1151A>G; p.Tyr384Cys) was identified in the LRP4 gene. Sanger validation confirmed that all affected individuals were homozygous and the obligate carriers were heterozygous for this variant. The variant is neither reported in 1000 human genomes, nor in 60 706 exomes databases, and is predicted as "pathogenic" by SIFT, Polyphen‐2 and MutationTaster software. Conclusions: The present study broadens the pathogenic spectrum of the LRP4 gene in syndactyly syndromes. WES is a powerful tool for genetic analysis in research and can be readily used as a first‐line diagnostic test in syndactyly and related phenotypes. [ABSTRACT FROM AUTHOR]

A reaction sequence involving three consecutive microwave-promoted continuous-flow reaction steps is presented to synthesize the title compounds (V) and (VII). [ABSTRACT FROM AUTHOR]

In this study, we utilized picosecond pulses from an Nd:YAG laser to investigate the nonlinear optical characteristics of monolayer MoSe2. Two-step growth involving the selenization of pulsed-laser-deposited MoO3 film was employed to yield the MoSe2 monolayer on a SiO2/Si substrate. Raman scattering, photoluminescence (PL) spectroscopy, and atomic force microscopy verified the high optical quality of the monolayer. The second-order susceptibility χ(2) was calculated to be ∼50 pm V−1 at the second harmonic wavelength [ABSTRACT FROM AUTHOR]