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1.
Med Humanit ; 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38238003

RESUMO

Lady health workers (LHWs) provide lifesaving maternal and child health services to >60% of Pakistan's population but are poorly compensated and overburdened. Moreover, LHWs' training does not incorporate efforts to nurture attributes necessary for equitable and holistic healthcare delivery. We developed an interdisciplinary humanities curriculum, deriving its strengths from local art and literature, to enhance character virtues such as empathy and connection, interpersonal communication skills, compassion and purpose among LHWs. We tested the curriculum's feasibility and impact to enhance character strengths among LHWs.We conducted a multiphase mixed-methods pilot study in two towns of Karachi, Pakistan. We delivered the humanities curriculum to 48 LHWs via 12 weekly sessions, from 15 June to 2 September 2021. We developed a multiconstruct character strength survey that was administered preintervention and postintervention to assess the impact of the training. In-depth interviews were conducted with a subset of randomly selected participating LHWs.Of 48 participants, 47 (98%) completed the training, and 34 (71%) attended all 12 sessions. Scores for all outcomes increased between baseline and endline, with highest increase (10.0 points, 95% CI 2.91 to 17.02; p=0.006) observed for empathy/connection. LHWs provided positive feedback on the training and its impact in terms of improving their confidence, empathy/connection and ability to communicate with clients. Participants also rated the sessions highly in terms of the content's usefulness (mean: 9.7/10; SD: 0.16), the success of the sessions (mean: 9.7/10; SD: 0.17) and overall satisfaction (mean: 8.2/10; SD: 3.3).A humanities-based training for front-line health workers is a feasible intervention with demonstrated impact of nurturing key character strengths, notably empathy/connection and interpersonal communication. Evidence from this study highlights the value of a humanities-based training, grounded in local literature and cultural values, that can ultimately translate to improved well-being of LHWs thus contributing to better health outcomes among the populations they serve.

2.
J Environ Manage ; 347: 119018, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37748293

RESUMO

Soil contamination and its subsequent impact on the food chain is a pressing challenge in the present day. The application of biochar has demonstrated a significant and positive effect on soil health, thereby enhancing plant growth and development. However, the application of biochar (BC) produced from negative pressure-induced carbonization to mitigate metal(loid) contamination is a new strategy that has been studied in current research. Results depicted that the application of biochar derived from the negative pressure carbonization (vacuum-assisted biochar (VBC) has a significant (p ≤ 0.05) positive impact on plant growth and physiological characteristics by influencing immobilization and speciation of metal(loid) in the soil system. Moreover, the interactive effect of VBC on physiological characteristics (photosynthesis, gas exchange, and chlorophyll contents) and antioxidant activities of maize (Zea mays L.) was significantly (p ≤ 0.05) positive by confining the translocation and movement of metal(loid)s to the aerial part of the maize plant. X-ray diffraction (XRD) provided information on the structural and chemical changes induced by the VBC-500 °C explaining metal(loid) adsorption onto mineral surfaces and complexation that can affect their mobility, availability, and toxicity in the contaminated soil. Fourier transform infrared spectroscopy (FTIR) further provided a more detailed understanding of the metal(loid)s and biochar complexation mechanisms influenced by VBC-based functional groups -OH, C-Hn, -COOH, CO, C-O-C, CC, C-O, C-H, OH, and C-C in the binding process. These results suggest that the application of biochar prepared at 500 °C under negative pressure-induced carbonization conditions to the soil is the most efficient way to reduce the uptake and transfer of metal(loid)s by influencing their mobility and availability in the soil-plant system.


Assuntos
Poluentes do Solo , Poluentes do Solo/análise , Carvão Vegetal/química , Metais/análise , Solo/química , Zea mays
3.
BMC Public Health ; 20(1): 1086, 2020 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-32652969

RESUMO

BACKGROUND: Inability to track children's vaccination history coupled with parents' lack of awareness of vaccination due dates compounds the problem of low immunization coverage and timeliness in developing countries. We evaluated the impact of two types of silicone immunization reminder bracelets for children in improving immunization coverage and timeliness of Pentavalent-3 and the Measles-1 vaccines. METHODS: Children < 3 months were enrolled in either of the 2 intervention groups (Alma Sana Bracelet Group and Star Bracelet Group) or the Control group. Children in the intervention groups were provided the two different bracelets at the time of recruitment. Each time the child visited the immunization center, a hole was perforated in the silicone bracelet to denote vaccine administration. Each child was followed up till administration of Measles-1 vaccine or till 12 months of age (if they did not come to the center for vaccination). Data was analyzed using the intention-to-treat population between groups. The unadjusted and adjusted Risk Ratios (RR) and 95% confidence interval (CI) for Pentavalent-3 and Measles-1 coverage at 12 months of age were estimated through bivariate and multivariate analysis. Time-to-Pentavalent-3 and Measles-1 immunization curves were calculated using the Kaplan-Meier method. RESULTS: A total of 1,445 children were enrolled in the study between July 19, 2017 and October 10, 2017. Baseline characteristics among the three groups were similar. Up-to-date coverage for the Pentavalent-3 /Measles-1 vaccine at 12 months of age was 84.6%/72.0%, 85.4%/70.5% and 83.0%/68.5% in Alma Sana Bracelet group, Star Bracelet group and Control group respectively but the differences were not statistically significant. In the multivariate analysis, neither the Alma Sana bracelet (adjusted RR = 1.01; 95% CI: 0.96-1.06), (adjusted RR: 1.05; 95% CI: 0.97-1.13) nor the Star bracelet (adjusted RR = 1.01; 95% CI: 0.96-1.06) (adjusted RR: 1.03; 95% CI: 0.95-1.11) was significantly associated with Pentavalent-3 vaccination or Measles-1 vaccination. CONCLUSION: Although we did not observe any significant impact of the bracelets on improved immunization coverage and timeliness, our findings add to the existing literature on innovative, low cost reminders for health and make several suggestions for enhancing practical implementation of these tools. TRIAL REGISTRATION: ClinicalTrials.gov NCT03310762 . Retrospectively Registered on October 16, 2017.


Assuntos
Promoção da Saúde/estatística & dados numéricos , Programas de Imunização/estatística & dados numéricos , Vacina contra Sarampo/administração & dosagem , Cooperação do Paciente/estatística & dados numéricos , Sistemas de Alerta/estatística & dados numéricos , Criança , Pré-Escolar , Feminino , Humanos , Imunização , Lactente , Masculino , Sarampo/prevenção & controle , Paquistão , Projetos de Pesquisa , Vacinação/estatística & dados numéricos , Cobertura Vacinal
4.
Ecotoxicol Environ Saf ; 191: 110244, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-32004946

RESUMO

The purpose of this research was to examine the influence of hydrothermally treated coal gangue (HTCG) with and without biochar (BC) on the leaching, bioavailability, and redistribution of chemical fractions of heavy metals (HMs) in copper mine tailing (Cu-MT). An increase in pH, water holding capacity (WHC) and soil organic carbon (SOC) were observed due to the addition of BC in combination with raw coal gangue (RCG) and HTCG. A high Cu and other HMs concentration in pore water (PW) and amended Cu-MT were reduced by the combination of BC with RCG and/or HTCG, whereas individual application of RCG slightly increased the Cu, Cd, and Zn leaching and bioavailability, compared to the unamended Cu-MT. Sequential extractions results showed a reduction in the exchangeable fraction of Cu, Cd, Pb, and Zn and elevation in the residual fraction following the addition of BC-2% and BC-HTCG. However, individual application of RCG slightly increased the Cu, Cd, and Zn exchangeable fractions assessed by chemical extraction method. Rapeseed was grown for the following 45 days during which physiological parameters, metal uptake transfer rate (TR), bioconcentration factor (BCF), and translocation factor (TF) were measured after harvesting. In the case of plant biomass, no significant difference between applied amendments was observed for the fresh biomass (FBM) and dry biomass (DBM) of shoots and roots of rapeseed. However, BC-2% and BC-HTCG presented the lowest HMs uptake, TR, BCF (BCFroot and BCFshoot), and TF for Cu, Cd, Cr, Ni, Pb, and Zn in rapeseed among the other amendments compared to the unamended Cu-MT. Overall, these findings are indicative that using biochar in combination with RCG and/or HTCG led to a larger reduction in HMs leaching and bioavailability, due to their higher sorption capacity and could be a suitable remediation strategy for heavy metals in a Cu-MT.


Assuntos
Brassica napus/efeitos dos fármacos , Carvão Vegetal/farmacologia , Carvão Mineral/análise , Metais Pesados/metabolismo , Mineração , Poluentes do Solo/metabolismo , Adsorção , Disponibilidade Biológica , Brassica napus/metabolismo , Carvão Vegetal/química , Cobre/análise , Cobre/metabolismo , Metais Pesados/análise , Solo/química , Poluentes do Solo/análise
5.
Ecotoxicol Environ Saf ; 187: 109845, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31654865

RESUMO

The extensive use of nano-fabricated products in daily life is releasing a large volume of engineered nanoparticles (ENPs) in the environment having unknown consequences. Meanwhile, little efforts have been paid to immobilize and prevent the entry of these emerging contaminants in the food chain through plant uptake. Herein, we investigated the biochar role in cerium oxide nanoparticles (CeO2NPs) bioaccumulation and subsequent translocation in wheat (Triticum aestivum L.) as well as impact on growth, photosynthesis and gas-exchange related physiological parameters. Results indicated that CeO2NPs up to 500 mg L-1 level promoted the plant growth by triggering photosynthesis, transpiration and stomatal conductance. Higher NPs concentration (2000 mg CeO2NPs L-1) has negatively affected the plant growth and photosynthesis related processes. Conversely, biochar amendment with CeO2NPs considerably reduced (~9 folds) the plants accumulated contents of Ce even at 2000 mg L-1 exposure level of CeO2NPs through surface complexation process and alleviated the phyto-toxic effects of NPs on plant growth. XPS and FTIR analysis confirmed the role of biochar-mediated carboxylate and hydroxyl groups bonding with CeO2NPs. These findings provides an inside mechanistic understanding about biochar interaction with nano-pollutants to inhibit their bioavailability to plant body.


Assuntos
Cério/análise , Carvão Vegetal/química , Nanopartículas/análise , Fotossíntese/efeitos dos fármacos , Poluentes do Solo/análise , Triticum/efeitos dos fármacos , Disponibilidade Biológica , Cério/metabolismo , Recuperação e Remediação Ambiental/métodos , Nanopartículas/metabolismo , Solo/química , Poluentes do Solo/metabolismo , Triticum/metabolismo
6.
BMC Public Health ; 19(1): 1421, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31666039

RESUMO

BACKGROUND: Inability to track children's vaccination history coupled with parents' lack of awareness of vaccination due dates compounds the problem of low immunization coverage and timeliness in developing countries. Traditional Reminder/Recall (RR) interventions such as paper-based immunization cards or mHealth based platforms do not yield optimal results in resource-constrained settings. There is thus a need for a low-cost intervention that can simultaneously stimulate demand and track immunization history to help reduce drop-outs and improve immunization coverage and timeliness. The objective of this study is to evaluate the impact of low-cost vaccine reminder and tracker bracelets for improving routine childhood immunization coverage and timeliness in Pakistani children under 2 years of age. METHODS: The study is an individually randomized, three-arm parallel Randomized Controlled Trial with two intervention groups and one control group. Infants in the two intervention groups will be given two different types of silicone bracelets at the time of recruitment, while infants in the control group will not receive any intervention. The two types of bracelets consist of symbols and/or numbers to denote the EPI vaccination schedule and each time the child will come for vaccination, the study staff will perforate a hole in the appropriate symbol to denote vaccine administration. Therefore, by looking at the bracelet, caregivers will be able to see how many vaccines have been received. Our primary outcome measure is the increase in coverage and timeliness of Pentavalent-3/PCV-3/Polio-3 and Measles-1 vaccine in the intervention versus control groups. A total of 1446 participants will be recruited from 4 Expanded Program on Immunization (EPI) centers in Landhi Town, Karachi. Each enrolled child will be followed up till the Measles-1 vaccine is administered, or till eleven months have elapsed since enrolment. DISCUSSION: Participant recruitment commenced on July 19, 2017, and was completed on October 10, 2017. Proposed duration of the study is 18 months and expected end date is December 1, 2018. This study constitutes one of the first attempts to rigorously evaluate an innovative, low-cost vaccine reminder bracelet. TRIAL REGISTRATION: ClinicalTrials.gov NCT03310762 . Retrospectively Registered on October 16, 2017.


Assuntos
Programas de Imunização/métodos , Esquemas de Imunização , Pais , Sistemas de Alerta , Cobertura Vacinal , Vacinação , Vacinas/administração & dosagem , Cuidadores , Pré-Escolar , Análise Custo-Benefício , Países em Desenvolvimento , Feminino , Humanos , Lactente , Masculino , Sarampo/prevenção & controle , Paquistão , Poliomielite/prevenção & controle , Ensaios Clínicos Controlados Aleatórios como Assunto , Sistemas de Alerta/instrumentação , Projetos de Pesquisa , Estudos Retrospectivos , População Urbana
7.
Environ Geochem Health ; 41(3): 1131-1162, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30298288

RESUMO

Airborne particulate matter (PM) that is a heterogeneous mixture of particles with a variety of chemical components and physical features acts as a potential risk to human health. The ability to pose health risk depends upon the size, concentration and chemical composition of the suspended particles. Potential toxic elements (PTEs) associated with PM have multiple sources of origin, and each source has the ability to generate multiple particulate PTEs. In urban areas, automobile, industrial emissions, construction and demolition activities are the major anthropogenic sources of pollution. Fine particles associated with PTEs have the ability to penetrate deep into respiratory system resulting in an increasing range of adverse health effects, at ever-lower concentrations. In-depth investigation of PTEs content and mode of occurrence in PM is important from both environmental and pathological point of view. Considering this air pollution risk, several studies had addressed the issues related to these pollutants in road and street dust, indicating high pollution level than the air quality guidelines. Observed from the literature, particulate PTEs pollution can lead to respiratory symptoms, cardiovascular problems, lungs cancer, reduced lungs function, asthma and severe case mortality. Due to the important role of PM and associated PTEs, detailed knowledge of their impacts on human health is of key importance.


Assuntos
Poluentes Atmosféricos/toxicidade , Poluição do Ar/análise , Exposição Ambiental/efeitos adversos , Material Particulado/toxicidade , Doenças Respiratórias/induzido quimicamente , Poluentes Atmosféricos/análise , Poluição do Ar/efeitos adversos , Asma/induzido quimicamente , Poeira , Humanos , Tamanho da Partícula , Material Particulado/análise , Medição de Risco , Saúde da População Urbana , Emissões de Veículos/análise , Emissões de Veículos/toxicidade
8.
J Environ Sci (China) ; 78: 29-41, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30665648

RESUMO

A series of new biochar-supported composite based on the combination of biochar and metallic nanoparticles (NPs) were produced through single-step pyrolysis of FeCl3-Ti(OBu)4 laden agar biomass under NH3 environment. The physiochemical properties of composites were characterized thoroughly. It has found that heating temperature and N-doping through NH3-ambiance pyrolysis significantly influence the visible-light sensitivity and bandgap energy of composites. The catalytic activities of composites were measured by degradation of Methylene Blue (MB) in the presence or absence of H2O2 and visible-light irradiation. Our best catalyst (N-TiO2-Fe3O4-biochar) exhibits rapid and high MB removal competency (99.99%) via synergism of adsorption, photodegradation, and Fenton-like reaction. Continuous production of O2- and OH radicles performs MB degradation and mineralization, confirmed by scavenging experiments and degradation product analysis. The local trap state Ti3+, Fe3O4, and N-carbon of the catalyst acted as active sites. It has suggested that the Ti3+ and N-doped dense carbon layer improve charge separation and shuttle that prolonged photo-Fenton like reaction. Moreover, the catalyst is highly stable, collectible, and recyclable up to 5 cycles with high MB degradation efficiency. This work provides a new insight into the synthesis of highly visible-light sensitized biochar-supported photocatalyst through NH3-ambiance pyrolysis of NPs-laden biomass.


Assuntos
Amônia/química , Carvão Vegetal/química , Azul de Metileno/química , Modelos Químicos , Pirólise , Poluentes Químicos da Água/química , Adsorção , Catálise , Peróxido de Hidrogênio/química , Titânio/química
9.
Ecotoxicol Environ Saf ; 149: 291-306, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29268101

RESUMO

Selenium (Se) is a trace mineral and an essential nutrient of vital importance to human health in trace amounts. It acts as an antioxidant in both humans and animals, immunomodulator and also involved in the control of specific endocrine pathways. The aim of this work is to provide a brief knowledge on selenium content in daily used various foodstuffs, nutritional requirement and its various health consequences. In general, fruits and vegetables contain low content of selenium, with some exceptions. Selenium level in meat, eggs, poultry and seafood is usually high. For most countries, cereals, legumes, and derivatives are the major donors to the dietary selenium intake. Low level of selenium has been related with higher mortality risk, dysfunction of an immune system, and mental failure. Selenium supplementation or higher selenium content has antiviral outcomes and is necessary for effective reproduction of male and female, also decreases the threat of chronic disease (autoimmune thyroid). Generally, some advantages of higher content of selenium have been shown in various potential studies regarding lung, colorectal, prostate and bladder cancers risk, nevertheless results depicted from different trials have been diverse, which perhaps indicates the evidence that supplementation will merely grant advantage if the intakes of a nutrient is deficient. In conclusion, the over-all people should be advised against the usage of Se supplements for prevention of cardiovascular, hepatopathies, or cancer diseases, as advantages of Se supplements are still ambiguous, and their haphazard usage could result in an increased Se toxicity risk. The associations among Se intake/status and health, or disease risk, are complicated and need exposition to notify medical practice, to improve dietary recommendations, and to develop adequate communal health guidelines.


Assuntos
Antioxidantes/análise , Alimentos/normas , Necessidades Nutricionais , Reprodução/efeitos dos fármacos , Selênio/análise , Oligoelementos/análise , Animais , Suplementos Nutricionais , Feminino , Humanos , Masculino , Risco
10.
Heliyon ; 10(8): e28714, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38638997

RESUMO

MIMO (Multiple-Input-Multiple-Output) antenna systems are promising for fifth-generation (5G) networks, offering lower latency and higher data rates. These systems utilize millimeter-wave (mmWave) frequency bands for efficient transmission and reception of multiple data simultaneously, enhancing overall efficiency and performance. This article presents a compact size, wide band tri-circular ring mmWave MIMO antenna with suitable performance characteristics for next-generation communication systems. The MIMO system consists of a tri-circular ring patch with slots on a ground plane. The four elements of the antenna are arranged together in the polarization diversity configuration with overall dimensions of 23×18×0.254 mm3, and designed on a 0.254 mm thin, flexible RO5880 substrate with a relative permittivity of 2.3 using Computer Simulation Technology (CST) 2022. The proposed antenna design shows the impedance bandwidth of 14 GHz with isolation >18 dB throughout the 26-40 GHz resonance band. The obtained gain is 6.6 dBi at 28 GHz with radiation efficiency > 90%. Several MIMO parameters are also investigated, such as Envelope Correlation Coefficient (ECC), Mean Effective Gain (MEG), Diversity Gain (DG), Total Active Reflection Co-efficient (TARC), and Channel Capacity Loss (CCL), and are found to be within the accepted limits for a practical MIMO system. Furthermore, the fabricated MIMO antenna was tested, and the measured results aligned favorably with the simulated results, confirming the suitability of the proposed design. Through the obtained results, the mmWave MIMO antenna is suitable for practical 5G as well as mmWave applications due to its lightweight, simple design, and wideband characteristics, which cover the 5G frequency bands of 26, 28, 32, and 38 GHz.

11.
Artigo em Inglês | MEDLINE | ID: mdl-38997471

RESUMO

We construct comparable indicators that measure the prevalence of recent intimate partner violence (IPV) using publicly available, integrated microdata within the IPUMS data collections across many countries. The objective of this work is to increase opportunities for comparative research by leveraging vast quantities of harmonized data. We use consistent and comparable variables that measure domestic violence in international health surveys. The most consistent indicators of domestic violence measure physical, psychological, and sexual IPV in the last 12 months. We imposed a consistent reference period and restricted to a comparable subpopulation where these differed across surveys. Aggregating IPV variables across surveys, without careful attention to question wording and subpopulations, may produce inconsistent measures leading to bias, over- or under-estimation of IPV prevalence, or spurious trends and associations. Using comparable indicators in microdata and studying the level, distribution, and covariates of IPV in multiple settings over time, we can better understand these phenomena and identify effective policy interventions.

12.
Int J Med Inform ; 181: 105288, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37979501

RESUMO

BACKGROUND: Gaps in information access impede immunization uptake, especially in low-resource settings where cutting-edge and innovative digital interventions are limited given the digital inequity. Our objective was to develop an Artificially Intelligent (AI) chatbot to respond to caregiver's immunization-related queries in Pakistan and investigate its feasibility and acceptability in a low-resource, low-literacy setting. METHODS: We developed Bablibot (Babybot), a local language immunization chatbot, using Natural Language Processing (NLP) and Machine Learning (ML) technologies with Human in the Loop feature. We evaluated the bot through a sequential mixed-methods study. We enrolled caregivers visiting the 12 selected immunization centers for routine childhood vaccines. Additional caregivers were reached through targeted text message communication. We assessed Bablibot's feasibility and acceptability by tracking user engagement and technological metrics, and through thematic analysis of in-depth interviews with 20 caregivers. FINDINGS: Between March 9, 2020, and April 15, 2021, 2,202 caregivers were enrolled in the study, of which, 677 (30.7%) interacted with Bablibot (users). Bablibot responded to 1,877 messages through 874 conversations. Conversation topics included vaccination due dates (32.4%; 283/874), side-effect management (15.7%;137/874), or delaying vaccination due to child's illness or COVID-lockdown (16.8%;147/874). Over 90% (277/307) of responses to text-based exit surveys indicated satisfaction with Bablibot. Qualitative analysis showed caregivers appreciated Bablibot's usefulness and provided feedback for further improvement of the system. CONCLUSION: Our results demonstrate the feasibility and acceptability of local-language NLP chatbots in providing real-time immunization information in low-resource settings. Text-based chatbots canminimize the workload on helpline operators, in addition to instantaneously resolving caregiver queries that otherwise lead to delay or default.


Assuntos
Cuidadores , Imunização , Criança , Humanos , Paquistão , Estudos de Viabilidade , Vacinação
13.
Micromachines (Basel) ; 14(9)2023 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-37763895

RESUMO

This paper introduces a novel two-port ultra-wideband (UWB) multiple-input multiple-output (MIMO) antenna system with enhanced isolation characteristics. The antenna, designed on a thin 0.787 mm RO5880 substrate, achieves a compact form factor of 52 × 26 mm2 and offers a wide bandwidth of 9.2 GHz (2.3 GHz to 11.5 GHz) while meeting the VSWR 2:1 criterion. Notably, the proposed antenna demonstrates an impressive increase in isolation, up to 16 dB, through the integration of a shared radiator with small rectangular slots, effectively reducing interference and improving overall performance. Furthermore, a comprehensive analysis of additional MIMO performance parameters, including the envelope correlation coefficient (ECC) and diversity gain, confirms their satisfactory limits, validating the potential of the proposed UWB-MIMO antenna for various UWB applications. The time domain analysis of the UWB antenna is also analyzed, and results are found to be within satisfactory limits. Simulation and measurement results further support the practicality and effectiveness of the antenna design, highlighting its compact size, wide bandwidth, and enhanced isolation characteristics, positioning it as a promising solution for advanced UWB microwave imaging systems.

14.
Micromachines (Basel) ; 14(4)2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-37421009

RESUMO

In this article, we propose a light weight, low profile Multiple Input Multiple Output (MIMO) antenna system for compact 5th Generation (5G) mmwave devices. Using a RO5880 substrate that is incredibly thin, the suggested antenna is made up of circular rings stacked vertically and horizontally on top of one another. The single element antenna board has dimensions of 12 × 12 × 0.254 mm3 while the size of the radiating element is 6 × 2 × 0.254 mm3 (0.56λ0 × 0.19λ0 × 0.02λ0). The proposed antenna showed dual band characteristics. The first resonance showed a bandwidth of 10 GHz with a starting frequency of 23 GHz to an ending frequency point of 33 GHz followed by a second resonance bandwidth of 3.25 GHz ranging from 37.75 to 41 GHz, respectively. The proposed antenna is transformed into a four element Linear array system with size of 48 × 12 × 0.254 mm3 (4.48λ0 × 1.12λ0 × 0.02λ0). The isolation levels at both resonance bands were noted to be >20 dB which shows high levels of isolation among radiating elements. The MIMO parameters such as Envelope Correlation Co-efficient (ECC), Mean Effective Gain (MEG) and Diversity Gain (DG) were derived and were found to be in satisfactory limits. The proposed MIMO system model is fabricated and through validation and testing of the prototype, the results were found to be in good agreement with simulations.

15.
Micromachines (Basel) ; 14(6)2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-37374738

RESUMO

This research work presents a compact design of a Multiple-Input Multiple-Output (MIMO) multiband antenna along with high-isolation characteristics. The presented antenna was designed for 3.50 GHz, 5.50 GHz, and 6.50 GHz frequencies for 5G cellular, 5G WiFi, and WiFi-6, respectively. The fabrication of the aforementioned design was undertaken using FR-4 (1.6 mm thickness) substrate material with a loss tangent and relative permittivity of about 0.025 and 4.30, respectively. The two-element MIMO multiband antenna was miniaturized to 16 × 28 × 1.6 mm3, making it desirable for devices operating in 5G bands. High isolation (>15 dB) was attained with thorough testing without employing a decoupling scheme in the design. Laboratory measurements resulted in a peak gain of 3.49 dBi and an efficiency of around 80% in the entire operating band. The evaluation of the presented MIMO multiband antenna was carried out in terms of the envelope correlation coefficient (ECC), diversity gain (DG), total active reflection coefficient (TARC), and Channel Capacity Loss (CCL). The measured ECC was less than 0.04, and the DG was well above 9.50. The observed TARC was also lower than -10 dB, and the CCL was below 0.4 bits/s/Hz in the entire operating band. The presented MIMO multiband antenna was analyzed and simulated using CST Studio Suite 2020.

16.
Environ Sci Pollut Res Int ; 30(32): 78279-78293, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37269518

RESUMO

An inexpensive and environmentally friendly composite synthesized from rice husk, impregnated with montmorillonite and activated by carbon dioxide, was investigated for the removal of azithromycin from an aqueous solution. Various techniques were used to characterize adsorbents in detail. The sorption process was primarily regulated by the solution pH, pollutant concentration, contact duration, adsorbent dose, and solution temperature. The equilibrium data were best analyzed using the nonlinear Langmuir and Sips (R2 > 0.97) isotherms, which revealed that adsorption occurs in a homogenous manner. The adsorption capacity of pristine biochar and carbon dioxide activated biochar-montmorillonite composite was 33.4 mg g-1 and 44.73 mg g-1, respectively. Kinetic studies identified that the experimental data obeyed the pseudo-second-order and Elovich models (R2 > 0.98) indicating the chemisorption nature of adsorbents. The thermodynamic parameters determined the endothermic and spontaneous nature of the reaction. The ion exchange, π-π electron-donor-acceptor (EDA) interactions, hydrogen-bonding, and electrostatic interactions were the plausible mechanisms responsible for the adsorption process. This study revealed that a carbon dioxide activated biochar-montmorillonite composite may be used as an effective, sustainable, and economical adsorbent for the removal of azithromycin from polluted water.


Assuntos
Bentonita , Poluentes Químicos da Água , Azitromicina , Cinética , Dióxido de Carbono , Poluentes Químicos da Água/análise , Carvão Vegetal/química , Termodinâmica , Água , Adsorção , Concentração de Íons de Hidrogênio
17.
Environ Sci Pollut Res Int ; 29(47): 71810-71825, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35604595

RESUMO

Organic and inorganic mixtures can be developed as immobilizing agents that could reduce heavy metal accumulation in crops and contribute to food safety. Here, inorganic materials (lime, L; zeolite, Z; and sepiolite, S) and organic materials (biochar, B, and compost, C) were selectively mixed to produce six composite soil amendments (LZBC, LSBC, LZC, LZB, LSC, and LSB). Given the fact that LZBC showed the best performance in decreasing soil Cd availability in the incubation experiment, it was further applied in the field condition with 14 vegetables as the test crops to investigate its effects on crop safety production in polluted greenhouse. The results showed that LZBC addition elevated rhizosphere soil pH by 0.1-2.0 units and reduced soil Cd availability by 1.85-37.99%. Both the biomass and the yields of edible parts of all vegetables were improved by LZBC addition. However, LZBC addition differently affected Cd accumulation in edible parts of the experimental vegetables, with the observation that Cd contents were significantly reduced in Allium fistulosum L., Amaranthus tricolor L., and Coriandrum sativum Linn., but increased in the three species of Lactuca sativa. Further health risk assessment showed that LZBC application significantly decreased daily intake of metal (DIM), health risk index (HRI), and target hazard quotient (THQ) for Cd in Allium fistulosum L., Amaranthus tricolor L., and Coriandrum sativum Linn., whereas increased all the indexes in Lactuca sativa. Our results showed that the effect of a composite amendment on Cd accumulation in different vegetables could be divergent and species-dependent, which suggested that it is essential to conduct a pre-experiment to verify applicable species for a specific soil amendment designed for heavy metal immobilization.


Assuntos
Metais Pesados , Oryza , Poluentes do Solo , Zeolitas , Cádmio/análise , Metais Pesados/análise , Solo/química , Poluentes do Solo/análise , Verduras
18.
Environ Pollut ; 293: 118510, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34793909

RESUMO

Plant growth regulators (PGRs) assisted phytoextraction was investigated as a viable phytoremediation technology to increase the phytoextraction efficiency in contaminated soils. This study aimed to evaluate the cadimum (Cd)/lead (Pb)/zinc (Zn) phytoextraction efficiency by a hyperaccumulator Sedum alfredii Hance (S. alfredii) treated with 9 PGRs, including indole-3-acetic acid (IAA), gibberellin (GA3), cytokinin (CKs), abscisic acid (ABA), ethylene (ETH), brassinosteroid (BR), salicylic acid (SA), strigolactones (SL) and jasmonic acid (JA), in slightly or heavily contaminated (SC and HC, respectively) soil. Results demonstrated that PGRs were able to improve S. alfredii biomass, the most significant increases were observed in GA3 and SL for HC soil, while for SC soil, IAA and BR exhibited positive effects. The levels of Cd, Pb and Zn in the shoots of S. alfredii treated with ABA and SL were noticeably greater than in the CK treatment in HC soil, while the uptake of metals were increased by IAA and CKs in SC soil. Combined with the results of biomass and metal contents in shoots, we found that ABA showed the highest Cd removal efficiency and the maximum Pb and Zn removal efficiency was observed with GA3, which was 62.99%, 269.23%, and 41.18%, respectively higher than the control in HC soil. Meanwhile, compared to control, the maximum removal efficiency of Cd by IAA treatment (52.80%), Pb by JA treatment (165.1%), and Zn by BR treatment (44.97%) in the SC soil. Overall, our results suggested that these PGRs, especially, ABA, SL, IAA, BR and GA3 had great potential in improving phytoremediation efficiency of S. alfredii grown in contaminated soils.


Assuntos
Metais Pesados , Sedum , Poluentes do Solo , Biodegradação Ambiental , Cádmio/análise , Chumbo , Metais Pesados/análise , Reguladores de Crescimento de Plantas , Solo , Poluentes do Solo/análise , Zinco/análise
19.
Sci Rep ; 12(1): 15317, 2022 09 12.
Artigo em Inglês | MEDLINE | ID: mdl-36097148

RESUMO

Soil organic matter (SOM) is of vital importance to soil health, and also plays a crucial role in the quality of the crops such as tobacco. However, the link between tobacco quality and SOM chemical compositions is still not well understood. To fill the information gap, we analyzed the quality of tobacco leaves and the corresponding SOM molecular compositions by electrospray ionization (ESI) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS), that were collected from six different sites in Bijie, Guizhou Province, China. The tobacco quality variedin six sites based on their chemical compositions. SOM compounds had a remarked impact on the quality of tobacco leaves and a distinct difference in SOM composition between low-quality and high-quality tobacco leaves was observed as well. Specifically, 105 common molecular formulas were detected in three SOM compounds of high-quality tobacco, which were more than those in low-quality samples. Although amino sugar, proteins, lipids, tannins, and carbohydrates had a collective influence on the chemical composition of tobacco leaves, the effect contributed by amino sugar and tannins was more prominent. In summary, fully understanding the association between tobacco chemical composition and SOM compounds can provide new insight into the regulation of tobacco quality and the sustainable development of agriculture.


Assuntos
Nicotiana , Solo , Agricultura , Amino Açúcares , Compostos Orgânicos/análise , Solo/química , Taninos
20.
Environ Pollut ; 309: 119768, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-35841993

RESUMO

As one of the most common ways to get rid of municipal waste, landfill leachate, waste with complicated compositions and high levels of contaminants, has become a significant threat to the world's environment. Here, the impact of sewage sludge (SS) and derived-biochar (SSB) amendments on the immobilization and potential mobility of heavy metals in a contaminated soil-plant system was investigated. The sequential fractionation findings showed that using SS-2%, SSB-2%, and SSBC-1% reduced the potential mobility of heavy metals while increasing the residual fraction in polluted soils. The translocation and bioconcentration factors showed that heavy metals were slightly transferred into shoots from roots and lowered accumulation in roots from contaminated soils. Fourier transform infrared (FTIR) and X-ray photoelectron spectrum (XPS) comprehensive characterization results indicated the significant role of applied amendments for heavy metals transformation from the exchangeable-soluble fractions to the least available form by lowering their mobility to confirm the adsorption-based complexes, which results in the surface adsorption of heavy metals with functional groups. The electron paramagnetic resonance (EPR) results indicated the dominance of reactive oxygen species (ROS) in the intracellular formation of hydroxyl radicals (•OH) in maize plant roots and shoots. ROS (•OH) generation plays a critical influence in the interaction between the physiological processes of plants and heavy metals. Moreover, all the amendments increased maize growth and biomass production. Our study suggests that alone and combined application of SS and SSB have great potential to remediate heavy metals contaminated soil for environmental sustainability.


Assuntos
Metais Pesados , Poluentes do Solo , Carvão Vegetal , Metais Pesados/análise , Plantas , Espécies Reativas de Oxigênio , Esgotos , Solo , Poluentes do Solo/análise , Zea mays
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