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1.
Heliyon ; 10(9): e30406, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38726180

RESUMO

Electroencephalogram (EEG) signals are critical in interpreting sensorimotor activities for predicting body movements. However, their efficacy in identifying intralimb movements, such as the dorsiflexion and plantar flexion of the foot, remains suboptimal. This study aims to explore whether various EEG signal quantities can effectively recognize intralimb movements to facilitate the development of Brain-Computer Interface (BCI) devices for foot rehabilitation. This research involved twenty-two healthy, right-handed participants. EEG data were collected using 21 electrodes positioned over the motor cortex, while two electromyography (EMG) electrodes recorded the onset of ankle joint movements. The study focused on analyzing slow cortical potential (SCP) and sensorimotor rhythms (SMR) in alpha and beta bands from the EEG. Five key features-fourth-order Autoregressive feature, variance, waveform length, standard deviation, and permutation entropy-were extracted. A modified Recurrent Neural Network (RNN) including Long Short-term Memory (LSTM) and Gated Recurrent Unit (GRU) algorithms was developed for movement recognition. These were compared against conventional machine learning algorithms, including nonlinear Support Vector Machine (SVM) and k Nearest Neighbourhood (kNN) classifiers. The performance of the proposed models was assessed using two data schemes: within-subject and across-subjects. The findings demonstrated that the GRU and LSTM models significantly outperformed traditional machine learning algorithms in recognizing different EEG signal quantities for intralimb movement. The study indicates that deep learning models, particularly GRU and LSTM, hold superior potential over standard machine learning techniques in identifying intralimb movements using EEG signals. Where the accuracies of LSTM for within and across subjects were 98.87 ± 1.80 % and 87.38 ± 0.86 % respectively. Whereas the accuracy of GRU within and across subjects were 99.18 ± 1.28 % and 86.44 ± 0.69 % respectively. This advancement could significantly benefit the development of BCI devices aimed at foot rehabilitation, suggesting a new avenue for enhancing physical therapy outcomes.

2.
PLoS One ; 19(3): e0300922, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38517921

RESUMO

Musca domestica L. (Muscidae: Diptera) is a human and livestock pest especially in tropical and sub-tropical areas. Different insecticides have been used to control this pest that pose serious harmful effects on humans and the environment. The current study was planned to investigate the effects of two concentrations (LC25 and LC50) of pyriproxyfen on biological and population parameters of a field strain of M. domestica. The exposed parents (F0) and their progeny (F1) were studied to examine the transgenerational effects. The results indicated that preadult duration was higher in control (13.68 days) compared to LC50 treated individuals (12.44 days). The male and female longevity was relatively lower in the LC25 treated population i.e. 24.62 and 26.62 days, respectively. The adult pre-oviposition period (APOP) and total pre-oviposition period (TPOP) values were higher in the LC25 treated individuals than those of control. Moreover, oviposition days and fecundity were reduced in the treated individuals as compared to the control treatment. A gradual decrease in the net reproductive rate (R0) was observed (8.46-14.07 per day) while the value of R0 was significantly higher in control. The results suggested that pyriproxyfen can be effectively utilized and incorporated in the management programs of M. domestica.


Assuntos
Moscas Domésticas , Inseticidas , Muscidae , Animais , Masculino , Feminino , Humanos , Piridinas/farmacologia , Reprodução , Inseticidas/farmacologia
3.
Parasitol Res ; 123(3): 157, 2024 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-38459281

RESUMO

Musca domestica Linnaeus is a devastating insect pest of medical and veterinary importance with reports of resistance development to commonly used insecticides worldwide. Rearing substrates usually play a crucial role in determining susceptibility to insecticides and control of insect pests. The aim of the present study was to investigate the effect of five rearing substrates of M. domestica on its susceptibility to different insecticides and activities of metabolic enzymes. After 30 generations of rearing, susceptibility of M. domestica to tested insecticides, viz., malathion, pirimiphos-methyl, alpha-cypermethrin, deltamethrin, methomyl, propoxur, spinetoram, and chlorfenapyr had evident differences. Musca domestica reared on hen liver exhibited reduced susceptibility to all insecticides followed by the strain reared on poultry manure. However, M. domestica reared on milk-based diet showed the highest susceptibility to tested insecticides followed by the strain reared on manures of buffalo and horse. In addition, M. domestica reared on different substrates exhibited significant differences (p < 0.01) in the activities of glutathione S-transferase (GST), cytochrome P450-dependent monooxygenase, and carboxylesterase (CarE). Overall, hen liver and poultry manure strains exhibited higher activities of metabolic enzymes than those of the milk-based diet, buffalo, and horse manure strains. In conclusion, the data of the present study exhibited a significant effect of rearing substrates on the susceptibility to insecticides and activities of metabolic enzymes in M. domestica. These results could be helpful for the sustainable management of M. domestica on different hosts by selecting appropriate insecticides.


Assuntos
Moscas Domésticas , Inseticidas , Animais , Feminino , Cavalos , Inseticidas/farmacologia , Esterco , Búfalos , Galinhas , Resistência a Inseticidas
4.
Ecotoxicology ; 33(2): 226-234, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38424316

RESUMO

The use of insecticides in agricultural settings often exerts negative effects on nontarget species. Methomyl, a broad-spectrum carbamate insecticide, is recommended to manage a number of insect pests of the cotton crop. Recently, Musca domestica, which is a nontarget insect species in cotton fields, has shown resistance to methomyl in Pakistan. The present study tried to assess resistance-risk assessment, rapidity of resistance development to methomyl, cross-resistance potential to other insecticides, resistance heritability and to forecast the projected rate of resistance development under field conditions. For this purpose, a field strain of M. domestica with 186 fold resistance to methomyl was re-selected in the laboratory for eight consecutive generations. Consequently, LD50 values increased rapidly (126.64 ng/fly to 3112.79 ng/fly) compared to those before selection experiments. Similarly, RR values increased from 186 to 3113 fold as a result of the selection process. However, resistance to methomyl did not remain stable when the selected strain (Meth-SEL) reared for the next five generations in a pesticide free environment. The Meth-SEL strain also developed cross-resistance to permethrin. The realized heritability (h2) value for the Meth-SEL strain was 0.39 with 27% average mortality of M. domestica. Assuming the standard deviation (σp) value 0.27 and the h2 value 0.39 for eight generations of continuous exposure to methomyl, then five, seven, eight, ten and twelve generations at 90, 80, 70, 60 and 50% selection intensity, respectively, would be required for a tenfold increase in the LD50 value of methomyl. In conclusion, the Meth-SEL strain of M. domestica exhibited a high risk of resistance development to methomyl under continuous selection pressure. Resistance increased rapidly during selection experiments that reflect the probability of resistance development under field conditions if M. domestica receive exposures to methomyl during its applications for the management of target pest species.


Assuntos
Moscas Domésticas , Inseticidas , Animais , Moscas Domésticas/genética , Inseticidas/toxicidade , Metomil , Permetrina , Medição de Risco , Resistência a Inseticidas/genética
5.
Children (Basel) ; 11(1)2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38255413

RESUMO

In this study, we assess healthcare providers' adherence to therapeutic drug monitoring (TDM) guidelines for gentamicin in neonates. Conducted at the Maternity and Children's Hospital in Makkah, Saudi Arabia, from July 2020 to July 2022, it retrospectively analyzed the compliance of healthcare workers in managing neonates treated with gentamicin. Covering 410 neonates, primarily diagnosed with respiratory distress (56%) and sepsis (32%), the study revealed that while a majority of trough and peak levels conformed to guidelines, substantial deviations were noted in cases of respiratory distress. This underlines the necessity for targeted TDM strategies, particularly in managing respiratory distress in neonates, to ensure optimal treatment efficacy and safety. The findings urge stringent compliance with TDM guidelines, emphasizing personalized approaches in neonatal gentamicin therapy for improved healthcare outcomes.

6.
Sci Rep ; 14(1): 245, 2024 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-38167477

RESUMO

Resistance to permethrin has been reported in Pakistani strains of Musca domestica. The present study explored the performance of biological traits and analyzed life tables to determine whether there is any detrimental effect of permethrin resistance on the fitness of permethrin-resistant strains [an isogenic resistant strain (Perm-R) and a field strain (Perm-F)] compared to a susceptible strain (Perm-S). Perm-R and Perm-F exhibited 233.93- and 6.87-fold resistance to permethrin, respectively. Life table analyses revealed that the Perm-R strain had a significantly shorter preadult duration, longer longevity, shorter preoviposition period, higher fecundity, finite rate of increase, intrinsic rate of increase, net reproductive rate and a shorter mean generation time, followed by the Perm-F strain when compared to the Perm-S strain. Data of the performance of biological traits reveled that permethrin resistance strains had a better fit than that of the Perm-S strain. The enhanced fitness of resistant strains of M. domestica may accelerate resistance development to permethrin and other pyrethroids in Pakistan. Some possible measures to manage M. domestica and permethrin resistance in situations of fitness advantage are discussed.


Assuntos
Moscas Domésticas , Inseticidas , Piretrinas , Animais , Permetrina/farmacologia , Inseticidas/farmacologia , Moscas Domésticas/genética , Resistência a Inseticidas/genética , Piretrinas/farmacologia
7.
J Knee Surg ; 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38113912

RESUMO

Soft-tissue balancing is an important factor in primary total knee arthroplasty (TKA), with 30 to 50% of TKA revisions attributed to technical operative factors including soft-tissue balancing. Robotic-assisted TKA (RATKA) offers opportunities for improved soft-tissue balancing methods. This study aimed to evaluate the repeatability and reproducibility of ligamentous laxity assessments during RATKA using a digital tensioner.Three experienced RATKA surgeons assessed preresection and trialing phases of 12 human cadaveric knees with varying degrees of arthritis. Ligamentous laxity was assessed with manual varus and valgus stresses in extension and flexion, with a digital tensioner providing feedback on the change of laxity displacement. Intraclass correlation coefficient (ICC) analyses were used to determine the repeatability within a single surgeon and reproducibility between the three surgeons.The results showed excellent repeatability and reproducibility in ligamentous laxity assessment during RATKA. Surgeons had excellent repeatability for preresection and trialing assessments, with median ICC values representing excellent reproducibility between surgeons. Surgeons were repeatable within 1 or 1.5 mm for preresection and trialing assessments. On average, the variation within a surgeon was 0.33 ± 0.26 mm during preresection and 0.29 ± 0.28 mm during trialing. When comparing surgeons to each other, they were reproducible within an average of 0.69 ± 0.33 mm for preresection and 0.65 ± 0.31 mm for trialing.This study demonstrated the reliability of robotic-assisted soft-tissue balancing techniques, providing control over ligamentous laxity assessments, and potentially leading to better patient outcomes. The digital tensioner used in this study provided excellent repeatability and reproducibility in ligamentous laxity assessment during RATKA, highlighting the potential benefits of incorporating robotics in TKA procedures.

8.
Open Vet J ; 13(10): 1283-1289, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38027406

RESUMO

Background: Since the first human case of Middle East Respiratory Syndrome (MERS) caused by Coronavirus (MERS-CoV) in 2012, several evidence bases have shown one-humped camels as the main reservoir host, from which infection is transmitted to humans. Aim: Serological investigation of MERS in dromedary camels in Wasit province (Iraq), detection severity of infection, and association to some risk factors. Methods: A total of 455 dromedary camels were selected randomly from two main districts in Wasit province, Iraq, during January and April (2023). Sera of all study camels were examined by enzyme-linked immunosorbent assay (ELISA), and titers of positive study animals were categorized according to their severity. Results: Serological testing yielded 37.58% positive animals for MERS infection. According to the severity of positive ODs (titer), a total of 53.22%, 30.99%, 12.28%, and 3.51% showed mild, moderate, strong, and very strong infections, respectively. Regarding risk factors, significant elevation in seropositivity was seen in camels of >3-6 and >6 years old and reduced in camels of £3 years old with an elevated risk of MERS with increased age. Regionally, seropositivity and relative risk were increased in the camels of Shaykh Sa'd when compared with Al-Numaniyah. Regarding sex, no significant variation was detected between seropositive females and males; however, male camels appeared at higher risk than females. Association between the severity of MERS infection and risk factors revealed that there was a significant increase in mild and moderate infections in female camels of >6 years old; whereas strong and very strong infections were seen in male camels of 33-6 years old. Mild and very strong infections were recorded in Shaykh Sa'd; while moderate and strong infections in Al-Numaniyah. Conclusion: The study indicated a longstanding existence of MERS-CoV in camels of Wasit province; therefore, recent infections or active viral excretion are required for confirmation by molecular approaches.


Assuntos
Infecções por Coronavirus , Coronavírus da Síndrome Respiratória do Oriente Médio , Animais , Humanos , Masculino , Feminino , Camelus , Iraque/epidemiologia , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/veterinária , Fatores de Risco
9.
Sci Rep ; 13(1): 18040, 2023 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-37872239

RESUMO

This study incorporated the index decomposition analysis to drive the GHGs emissions intensity and separate the impact into true efficiency and structural transformation of economic activities on GHGs emissions. The global perspective is investigated in three aspects; (i) global groups of countries regarding income level, (ii) global countries bifurcated into geo-political regions and, (iii) hundred countries are taken to perform individual country level analysis, by taking 20 years (2000-2019) data. The hundred countries are ranked regarding GHGs intensity, efficiency and economic activities with respect to (i) for the latest year performance, (ii) twenty years average performance and, (iii) annual average reduction of GHGs emissions, comparable with base year 2000. Income-based countries groups explicate the improvement of GHGs intensity for HIC only and the economic transformation contributed to it. Efficiency index for all income groups while economic activities of LMIC, MIC and UMIC deteriorated the GHGs emissions. Global geo-political regions explicate the mixed pattern of GHGs intensity. Efficiency index is best for Azerbaijan and least for Uzbekistan. While ranking average GHGs emission reduction countries; Zimbabwe is the best and Qatar is the last country in the intensity list.

10.
Plants (Basel) ; 12(16)2023 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-37631216

RESUMO

Due to ongoing human activities, heavy metals are heavily accumulated in the soil. This leads to an increase in the discharge and the quick spread of heavy metal pollution in human settlements and natural habitats, having a disastrous effect on agricultural products. The current experiment was planned to evaluate the effect of lead-tolerant-plant-growth-promoting rhizobacteria (LTPGPR) on growth, yield, antioxidant activities, physiology, and lead uptake in the root, shoot, and seed of Indian mustard (Brassica juncea) in lead-amended soil. Three pre-isolated well-characterized lead-tolerant rhizobacterial strains-S10, S5, and S2-were used to inoculate seeds of Indian mustard grown at three different levels of lead (300 mg kg-1, 600 mg kg-1, 900 mg kg-1) contaminated soil. The experiment was designed following a completely randomized design (CRD) under factorial arrangements. Lead nitrate was used as a source of lead contamination. At harvesting, data regarding growth, physiology, yield per plant, antioxidant activities, malondialdehyde and proline content, and lead uptake in the root, shoot, and seed of Indian mustard were recorded. Results demonstrated that lead contamination at all levels significantly reduced the plant growth, yield, and physiological processes. Plants inoculated with lead-tolerant rhizobacteria showed a significant improvement in plant growth, yield, antioxidant activities, and physiological attributes and cause a valuable reduction in the malondialdehyde contents of Indian mustard in lead-contaminated soil. Moreover, plants inoculated with lead-tolerant rhizobacteria also showed an increment in lead uptake in the vegetative parts and a significant reduction of lead contents in the seed of Indian mustard.

11.
Sci Rep ; 13(1): 13181, 2023 08 14.
Artigo em Inglês | MEDLINE | ID: mdl-37580401

RESUMO

Chitinase-producing fungi have now engrossed attention as one of the potential agents for the control of insect pests. Entomopathogenic fungi are used in different regions of the world to control economically important insects. However, the role of fungal chitinases are not well studied in their infection mechanism to insects. In this study, Chitinase of entomopathogenic fungi Trichoderma longibrachiatum was evaluated to control Aphis gossypii. For this purpose, fungal chitinase (Chit1) gene from the genomic DNA of T. longibrachiatum were isolated, amplified and characterised. Genomic analysis of the amplified Chit1 showed that this gene has homology to family 18 of glycosyl hydrolyses. Further, Chit1 was expressed in the cotton plant for transient expression through the Geminivirus-mediated gene silencing vector derived from Cotton Leaf Crumple Virus (CLCrV). Transformed cotton plants showed greater chitinase activity than control, and they were resistant against nymphs and adults of A. gossypii. About 38.75% and 21.67% mortality of both nymphs and adults, respectively, were observed by using Chit1 of T. longibrachiatum. It is concluded that T. longibrachiatum showed promising results in controlling aphids by producing fungal chitinase in cotton plants and could be used as an effective method in the future.


Assuntos
Afídeos , Quitinases , Animais , Gossypium/genética , Gossypium/metabolismo , Afídeos/genética , Quitinases/genética , Quitinases/metabolismo , Insetos/metabolismo
12.
Sci Rep ; 13(1): 7074, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-37127684

RESUMO

Insecticides are an integral part of most of the cropping systems worldwide; however, these usually exert negative impact on the environment and non-target insects as well. Non-target insects are prone to develop resistance to insecticides due to prolonged and repeated lethal and sublethal exposures. Musca domestica is a common non-target, pollinator and nectar feeder species in cotton ecosystem, besides its status as a public health pest in human habitations. In the present work, resistance to methomyl, one of the major insecticides used for cotton pest management, was assessed in 20 M. domestica strains from the major cotton producing areas of the Punjab and Sindh provinces of Pakistan. The results revealed that toxicity values of methomyl for Punjabi and Sindhi strains ranged from 28.07 to 136.16 µg fly-1 and 29.32 to 136.87 µg fly-1, respectively. Among Punjabi strains, D.G. Khan, Lodhran, Bahawalpur, Toba Tek Singh, Bahawalnagar, Rajanpur and Jhang strains exhibited very high levels of resistance (RR > 100) to methomyl; Bhakkar, Kasur, Vehari, Layyah, Muzaffargarh and R.Y. Khan showed high resistance (RR = 51-100 fold), while the Mianwali strain showed a moderate level of resistance to methomyl (RR = 36.45 fold). In case of Sindhi strains, very high levels of resistance (> 100 fold) were reported for Sukkar and Sanghar strains, high levels of resistance (RR 51-100 fold) for Khairpur, Jamshoro and Ghotki, and moderate resistance to methomyl (38.08 fold) in the Dadu strain. There was a significant synergism of methomyl toxicity in all field strains when methomyl bioassayed along with piperonyl butoxide (PBO) and S,S,S-tributylphosphorotrithioate (DEF) providing clues of metabolic-based mechanisms of resistance to methomyl. In conclusion, insecticides used in crop farming can cause resistance development in non-target M. domestica. It is necessary to adopt the pest management activities that are safe for the environment and non-target insect species.


Assuntos
Moscas Domésticas , Inseticidas , Animais , Humanos , Inseticidas/farmacologia , Metomil , Paquistão , Ecossistema , Resistência a Inseticidas
13.
Sci Total Environ ; 871: 162023, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-36739032

RESUMO

Soil pollution caused by complex organochloride mixtures has been increasing in many parts of the world in recent years; as a result, countless numbers of people are exposed to dangerous pollutions; hence, the treatment of organochlorides-polluted soils is gaining considerable attention. In this study, the potential of unactivated peroxymonosulfate (KHSO5) in remediating soil co-contaminated with trichlorophenol, para-dichlorobenzene, and para-chloro-meta-cresol was investigated. In addition, the treatment's collateral effect on critical soil properties was explored. The result revealed that treating 10 g of soil with 20 mL of 5 mM KHSO5 for 60 min could oxidize 70.49% of the total pollutants. The pH of the soil was decreased following the treatment. The significant decrease, (p < 0.05), in the soil organic matter following the remediation has affected cation exchange capacity, and available nitrogen. It was also observed that the treatment reduced the ß-glucosidase, urease, invertase, and cellulase activities significantly, (p < 0.05). The treatment, on the other hand, brought negligible effects on available phosphorus, available potassium, and particle size distribution. The phytotoxicity tests, which included seed germination and root elongation and soil respiration tests revealed that the treatment did not leach toxins into the treated soil. The treatment method was found to be relatively ecofriendly and cost effective.


Assuntos
Poluentes Ambientais , Recuperação e Remediação Ambiental , Poluentes do Solo , Humanos , Solo/química , Poluentes do Solo/análise , Poluição Ambiental/análise , Compostos Orgânicos
14.
Curr Pollut Rep ; 9(1): 46-59, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36743476

RESUMO

Purpose of Review: In the context of COVID-19 sweeping the world, the development of microbial disinfection methods in gas, liquid, and solid media has received widespread attention from researchers. As a disinfection technology that can adapt to different environmental media, microwave-assisted disinfection has the advantages of strong permeability, no secondary pollution, etc. The purpose of this review is to put forward new development requirements for future microwave disinfection strategies by summarizing current microwave disinfection methods and effects. From the perspective of the interaction mechanism of microwave and microorganisms, this review provides a development direction for more accurate and microscopic disinfection mechanism research. Recent Findings: Compared to other traditional environmental disinfection techniques, microwave-assisted disinfection means have the advantages of being more destructive, free of secondary contamination, and thorough. Currently, researchers generally agree that the efficiency of microwave disinfection is the result of a combination of thermal and non-thermal effects. However, the performance of microwave disinfection shows the differences in the face of different environmental media as well as different types of microorganisms. Summary: This review highlights the inactivation mechanism of microwave-assisted disinfection techniques used in different scenarios. Suggestions for promoting the efficiency and overcoming the limitations of low energy utilization, complex reactor design, and inaccurate monitoring methods are proposed.

15.
J Pak Med Assoc ; 73(2): 405-406, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36800738

RESUMO

The clinical presentation of COVID-19 varies from being asymptomatic to developing acute respiratory distress syndrome and multi-organ dysfunction. The diffuse microvascular thrombi in multiple organs seen in the autopsy of COVID-19 patients are similar to that of thrombotic microangiopathy (TMA). TMA is characterised by thrombus formation in the microvasculature with laboratory findings of microangiopathic haemolytic anaemia (MAHA) and thrombocytopenia. A 49-year-old male presented to the Aga Khan University Hospital, Karachi. with fever, diarrhoea, altered level of consciousness, and a positive nasopharyngeal swab for SARS-CoV-2. He developed severe thrombocytopenia, MAHA with 5.8% schistocytes, and worsening renal function on the sixth day of admission. Diagnosis of thrombotic thrombocytopenic purpura (TTP) was established based on PLASMIC score, and he was successfully treated with intravenous (IV) Methylprednisolone, therapeutic plasma exchange and IV Rituximab. The case emphasises the need to keep TTP in the differential diagnosis when a patient with COVID-19 develops severe thrombocytopenia, acute renal failure, or impaired level of consciousness, since prompt diagnosis and treatment is necessary to gain favourable outcome.


Assuntos
COVID-19 , Epidermólise Bolhosa Adquirida , Falência Renal Crônica , Púrpura Trombocitopênica Trombótica , Masculino , Humanos , Pessoa de Meia-Idade , Epidermólise Bolhosa Adquirida/complicações , Epidermólise Bolhosa Adquirida/diagnóstico , Epidermólise Bolhosa Adquirida/tratamento farmacológico , COVID-19/complicações , SARS-CoV-2 , Púrpura Trombocitopênica Trombótica/complicações , Púrpura Trombocitopênica Trombótica/diagnóstico , Púrpura Trombocitopênica Trombótica/terapia
16.
PLoS One ; 18(1): e0280469, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36662794

RESUMO

In this article, a single-layer metasurface based reflector design is proposed for linear-to-linear cross-polarization conversion in microwave frequency range. The unit-cell of the proposed design consists of triple-arrow resonant design printed on a grounded FR4 substrate. Excellent cross-conversion is achieved over a broad frequency range (8.0-18.50 GHz) with polarization conversion efficiency higher than 90%. The proposed design has a large fractional bandwidth (FBW) of 80% due to three resonances occurring in the band. The polarization response is angularly stable with respect to oblique incidences with incidence angles up to 45°. The proposed design has been fabricated and experimentally validated. The measurement results are in good agreement with the simulation results.


Assuntos
Micro-Ondas , Refração Ocular , Simulação por Computador , Vibração
17.
Environ Sci Pollut Res Int ; 30(11): 29921-29928, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36422779

RESUMO

Indiscriminate use of insecticides in food storage facilities for controlling insect pests has deleterious effects on the environment and non-targeted organisms in the premises. Continuous use of insecticides may result in resistance development in insect pests, which compel the stakeholders to increase the dosage of insecticides to manage resistant insect pests. The increased dosage of insecticides ultimately may result in contamination of stored food stuff that affects human health. The present study was planned to generate data that will be helpful to delay resistance development and to reduce environmental pollution. A field strain of Sitophilus oryzae, one of the most common insect pests of stored foodstuff, was selected separately with pirimiphos-methyl, permethrin, or spinosad for five consecutive generations. The selected strains were studied for resistance risk assessment, time taken to develop resistance to insecticides after continuous exposure in the selection process, preliminary mechanism of resistance, and whether the development of resistance due to the selection with a particular insecticide could develop cross-resistance to other insecticide or not. In comparison to a laboratory susceptible reference strain, the insecticide-selected strains revealed rapid development of resistance against insecticides as a result of selection process: 31.05-fold resistance to pirimiphos-methyl, 156.49-fold resistance to permethrin, and 65.6-fold resistance to spinosad. The selected strains did not show cross-resistance to insecticides to with these strains were not exposed during selection experiments, i.e., strain selected with pirimiphos-methyl did not show cross-resistance to spinosad and permethrin. In the synergism bioassays, the synergists (S,S,S-tributyl phosphorotrithioate and piperonyl butoxide) significantly reduced resistance of the selected strain against insecticides to with these were selected, revealing the probability of metabolic mechanism of resistance. The present study revealed high risks of resistance development to pirimiphos-methyl, spinosad, and permethrin under consistent selection pressure. Lack of cross-resistance among insecticides provides an opportunity to use insecticides in rotation instead of increasing dosages to manage resistant insects that will ultimately pollute the environment.


Assuntos
Inseticidas , Animais , Humanos , Inseticidas/farmacologia , Permetrina/farmacologia , Resistência a Inseticidas , Insetos , Medição de Risco
18.
Adv Mater ; 35(25): e2208789, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36563307

RESUMO

Small-molecule organic single crystals (SCs) with an inherent in-plane anisotropic nature enable direct linearly polarized light emission without the need for spatially separated polarizers and complex optical structures. However, the device performance is severely restricted by the starvation of appropriate SC emitters and the difficulty in the construction of efficient SC electroluminescence (EL) devices, leading to a low external quantum efficiency (EQE) of usually smaller than 1.5%. Here, highly efficient inherent linearly polarized light-emitting diodes (LP-LEDs) are demonstrated by exploiting 2,6-diphenylanthracene (DPA) SCs as intrinsically polarized emitters. The LP-LEDs exhibit a 2.5-fold enhanced maximum EQE of 3.38%, which approaches the theoretical limit for the DPA SC-based EL device and is the highest among organic SC-based LEDs reported thus far. More importantly, a high degree of polarization (DOP) up to 0.74 is achieved for the intrinsically polarized EL emission of the DPA SC-based LP-LEDs. By leveraging the highly efficient LP-LED, an interchip polarized optical communication system consisting of organic SCs is demonstrated for the first time. This work creates a solid foundation for the exploitation of a vast new library of small-molecule organic SCs for LP-LEDs and carries broad implications for polarized optics and relevant optoelectronic devices.

19.
Toxics ; 12(1)2023 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-38276715

RESUMO

Cyromazine is a triazine insect growth regulator insecticide that is recommended for control of Musca domestica worldwide. Cyromazine is highly effective in causing mortality of M. domestica; however, some aspects of its lethal and sublethal effects on the biology of M. domestica are still unknown. The present study explored lethal and sublethal effects on several biological traits and population parameters of M. domestica. Concentration-response bioassays of cyromazine against third-instar larvae of M. domestica exhibited sublethal and lethal effects from concentrations of 0.03 (LC10), 0.06 (LC25), and 0.14 (LC50) µg/g of a larval medium. Exposure of M. domestica larvae to these concentrations resulted in reduced fecundity, survival, longevity and oviposition period, and delayed development of immature stages (i.e., egg hatch time and larval and pupal durations) in the upcoming generation of M. domestica. The values of population parameters such as intrinsic rate of increase, finite rate of increase, net reproductive rate, age-specific survival rate and fecundity, and age-stage life expectancy and reproductive value, analyzed using the age-stage and two-sex life table theory, were significantly reduced in a concentration-dependent manner in comparison with the control group. In conclusion, the study highlights the significant effects of cyromazine on the biology of M. domestica that could help suppress its population in cases of severe infestations.

20.
Insects ; 13(12)2022 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-36555079

RESUMO

For environment-friendly, safe and nonpersistent chemical control of a significant polyphagous insect pest, Helicoverpa armigera, discovery of growth-regulating xenobiotics can offer a sustainable alternative to conventional insecticides. For this purpose, chemically synthesized compounds to inhibit sterol carrier protein (SCP-2) function using in silico and in vivo assays were evaluated to estimate their impact on the survivals and lifetable indices of H. armigera. From nine chemically synthesized compounds, OA-02, OA-06 and OA-09 were selected for this study based on binding poses mimicking cholesterol, a natural substrate of sterol carrier protein and molecular dynamics simulations. In vivo bioassays revealed that all compounds significantly reduced the larval and pupal weight accumulations and stadia lengths. Subsequently, the pupal periods were prolonged upon treatment with higher doses of the selected compounds. Moreover, OA-09 significantly reduced pupation and adult emergence rates as well as the fertility of female moths; however, fecundity remained unaffected, in general. The life table parameters of H. armigera were significantly reduced when treated with OA-09 at higher doses. The population treated with 450 µM of OA-09 had the least net reproductive rates (Ro) and gross reproductive rate (GRR) compared to the control population. The same compound resulted in a declining survival during the early stages of development coupled with reduced larval and pupal durations, and fertility. These results have a significant implication for developing an effective and sustainable chemical treatment against H. armigera infestation.

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