Unveiling the efficacy of Bacillus faecalis and composted biochar in alleviating arsenic toxicity in maize.

Arsenic (As) contamination is a major environmental pollutant that adversely affects plant physiological processes and can hinder nutrients and water availability. Such conditions ultimately resulted in stunted growth, low yield, and poor plant health. Using rhizobacteria and composted biochar (ECB) can effectively overcome this problem. Rhizobacteria have the potential to enhance plant growth by promoting nutrient uptake, producing growth hormones, and suppressing diseases. Composted biochar can enhance plant growth by improving aeration, water retention, and nutrient cycling. Its porous structure supports beneficial microorganisms, increasing nutrient uptake and resilience to stressors, ultimately boosting yields while sequestering carbon. Therefore, the current study was conducted to investigate the combined effect of previously isolated Bacillus faecalis (B. faecalis) and ECB as amendments on maize cultivated under different As levels (0, 300, 600 mg As/kg soil). Four treatments (control, 0.5% composted biochar (0.5ECB), B. faecalis, and 0.5ECB + B. faecalis) were applied in four replications following a completely randomized design. Results showed that the 0.5ECB + B. faecalis treatment led to a significant rise in maize plant height (~ 99%), shoot length (~ 55%), root length (~ 82%), shoot fresh (~ 87%), and shoot dry weight (~ 96%), root fresh (~ 97%), and dry weight (~ 91%) over the control under 600As stress. There was a notable increase in maize chlorophyll a (~ 99%), chlorophyll b (~ 81%), total chlorophyll (~ 94%), and shoot N, P, and K concentration compared to control under As stress, also showing the potential of 0.5ECB + B. faecalis treatment. Consequently, the findings suggest that applying 0.5ECB + B. faecalis is a strategy for alleviating As stress in maize plants.

Triangular metallic ring-shaped broadband polarization-insensitive and wide-angle metamaterial absorber for visible regime.

The inherent bandwidth limitations make it quite challenging to achieve the wideband response of metamaterial absorbers. In this paper, a metamaterial absorber based on triangular metallic rings has been proposed to attain wideband absorption (>90%) in the wavelength span of 400-750 nm. The absorber is constituted of periodically placed unit cells, where each unit cell contains three concentric triangular chromium metal rings. The absorption of the design remains stable (above 70%) over a wide range of incidence obliquity (0°-60°) under transverse electric (TE) and transverse magnetic (TM) polarization. Further, the absorber shows polarization-insensitive behavior over different polarization states. The low-cost and thermally endurable chromium metal, wide absorption, and wide-angle stability make the proposed absorber a suitable candidate for applications like solar energy harvesting, solar detectors, solar thermal photovoltaics, and photonic devices.

A Novel Meander Line Metamaterial Absorber Operating at 24 GHz and 28 GHz for the 5G Applications.

Fifth generation (5G) communication systems deploy a massive MIMO technique to enhance gain and spatial multiplexing in arrays of 16 to 128 antennas. In these arrays, it is critical to isolate the adjacent antennas to prevent unwanted interaction between them. Fifth generation absorbers, in this regard, are the recent interest of many researchers nowadays. The authors present a dual-band novel metamaterial-based 5G absorber. The absorber operates at 24 GHz and 28 GHz and is composed of symmetric meander lines connected through a transmission line. An analytical model used to calculate the total number of required meander lines to design the absorber is delineated. The analytical model is based on the total inductance offered by the meander line structure in an impedance-matched electronic circuit. The proposed absorber works on the principal of resonance and absorbs two 5G bands (24 GHz and 28 GHz). A complete angular stability analysis was carried out prior to experiments for both transverse electric (TE) and transverse magnetic (TM) polarizations. Further, the resonance conditions are altered by changing the substrate thickness and incidence angle of the incident fields to demonstrate the functionality of the absorber. The comparison between simulated and measured results shows that such an absorber would be a strong candidate for the absorption in millimetre-wave array antennas, where elements are placed in proximity within compact 5G devices.

Polarization-insensitive dual-wideband fractal meta-absorber for terahertz applications.

Terahertz (THz) metamaterial absorbers have realized a prodigious reputation due to the limitation of natural absorbing materials in this range. Getting wideband absorption characteristics is challenging and arduous, especially in the THz band. Self-similar repeated fractal elements offer a promising solution to attain broadband absorption response due to their inherent multiple resonance characteristics. Therefore, by captivating the advantage of fractal geometry, we proposed a dual and wideband meta-absorber operating in the THz regime. The metamaterial absorber design comprises the assembly of self-similar square-shaped blocks arranged in a specific pattern to construct the fractal geometry. The proposed THz absorber demonstrates 90% absorption under normal incident waves for two operating bands from 9.5-10.55 THz and 12.3-13.35 THz. The suggested metamaterial absorber also shows good and stable absorption responses under different oblique incidence angles for transverse electric (TE) and transverse magnetic (TM) wave polarization. Moreover, this absorber manifests over 85% absorptivity in its entire operating range (9-14 THz) under the incidence angle of 60° and 70° for TM mode. Furthermore, it gives a polarization-insensitive behavior under the effect of different polarization angles. This kind of wideband absorber catches fascinating applications in THz detection, imaging, cloaking, and optoelectronic devices.

Conductive metal-oxide-based tunable, wideband, and wide-angle metamaterial absorbers operating in the near-infrared and short-wavelength infrared regions.

This paper investigates the absorption features of the gallium-doped zinc oxide (GZO) nanowire-based metamaterial absorber. The absorption spectrum was analyzed in the near-infrared regime (NIR) and short-wavelength infrared regime (SWIR). The wideband absorption was observed in the NIR and SWIR. The effect of the volume fraction of the nanorod and thickness of the metamaterial was depicted on the absorption spectrum. Observations reveal that at a lower volume fraction of GZO, absorption is noticed at SWIR of the spectrum; however, for a large volume fraction, blueshift in the absorption band is noticed, and absorption is found in the NIR of the spectrum. Further, a larger volume fraction of GZO attributes to the property of hyperbolic metamaterial. Moreover, the figure of merit and operational bandwidth are analyzed to optimize the absorption results. Such an absorber would be useful for energy harvesting, SWIR photodetectors, and imaging applications.

Insights on the effects of patient perceptions and awareness on ambulance usage in Karachi, Pakistan.

BACKGROUND: Prehospital care is a vital part of emergency medical care. Countries with decentralised ambulance systems, such as Pakistan, require patient knowledge as to when to call an ambulance and which service to call. Little is known about how patient perceptions of ambulance services affect ambulance usage in most low- and middle-income countries (LMIC). The purpose of our study was to analyse patient perspectives of the ambulance system in Karachi to understand how to improve ambulance use. METHODS: Indepth interviews were conducted with 30 individuals selected by convenience sampling representing patients who came to the emergency department by private transport versus one of two of the main ambulance service providers in Karachi. RESULTS: Similar to what has been shown in some LMIC contexts, two of the major themes that emerged which affect patient decision making with regard to ambulance use were a mistrust of the ambulance system or providers and a sense of inadequacy of the local system as compared with international standards. In addition, which has not been shown in previous studies, there was a fundamental misunderstanding of the role of ambulance services in the healthcare infrastructure. CONCLUSIONS: Insight into the main issues affecting patient decisions to use an ambulance service offers possible targets for patient education that could result in an increase in the proper usage of ambulances and thus optimise outcomes from serious injury and illness in an LMIC context.

Unusual trajectory of a bullet from the shoulder to the brain: an emergency department perspective on finding a missing bullet.

Terminal ballistics continues to struggle with bullet trajectory reconstruction and interpretation. This is a case of a young man presented with a very unusual trajectory of a bullet from the left shoulder to the brain parenchyma. The single wound and altered mentation prompted a CT head and neck scan, which revealed a retained bullet in the brain parenchyma, traversing from the left shoulder, across the neck and into the brain without causing significant damage to vital organs. We managed the patient conservatively. Emergency physicians dealing with gunshot injuries should thoroughly search for the bullet in cases where only a single wound is present and the bullet is missing, and they should have a basic understanding of the ballistics to understand the mechanism and injury pattern sustained by the bullet. This atypical ballistic trajectory scenario emphasises the need to exercise vigilance in accurately predicting the trajectory when the ballistic route is unknown.

Exploring the relationship between intimate partner violence during pregnancy and stillbirths.

INTRODUCTION: The relationship between intimate partner violence (IPV) in pregnancy and stillbirths is poorly understood. We aimed to determine if there was any association between stillbirths and IPV during pregnancy. METHODS: A community-based, matched, case-control study was conducted in 2014, nested within the Maternal and Newborn Health Registry of the Global Network for Women's and Children's Health Research in Pakistan. Using a WHO questionnaire, IPV in pregnancy was ascertained from 256 cases (women with stillbirths) and 539 controls (women with live births), individually matched on parity. Multivariable conditional logistic regression analysis assessed the association of IPV in pregnancy ending in stillbirths compared to those with live births. RESULTS: The effect of physical and psychological IPV was modified by maternal age. Among women 25-34 years old with stillbirths, the odds of experiencing physical IPV in pregnancy were four times greater than those with live births, after controlling for confounders [odds ratio 4.1 (95% CI: 1.5, 11.2)]. A negative association was observed between psychological IPV in pregnancy and stillbirths among women younger than 25 years, and no association was observed between sexual IPV during pregnancy and stillbirths. CONCLUSION: Study results show that women 25-34 years of age with stillbirths were four times more likely to experience physical IPV during pregnancy. Further studies replicating the effect modification of IPV by maternal age are warranted.

Return of spontaneous circulation and survival at hospital discharge in patients with out-of-hospital and emergency department cardiac arrests in a tertiary care centre.

OBJECTIVE: To examine clinical variables and outcomes in patients with out-of-hospital (unwitnessed) and emergency department (ED; witnessed) cardiac arrests at a tertiary care hospital in Karachi. METHODS: A prospective observational study was conducted to note that outcomes in patients with first attempted cardiopulmonary resuscitation in the Emergency Department of the Aga Khan University Hospital, Karachi, between Jan. 2000 and Dec. 2000. Cardiac arrest was defined as absence of a palpable central pulse and apnoea. Return of spontaneous circulation (ROSC) and survival at hospital discharge were primary outcomes. Logistic regression was applied to determine predictors for ROSC. RESULTS: Of 106 patients with cardiac arrest, 59% (n = 62/106) patients had ROSC [52% (n = 29/56) of unwitnessed group; 64% (n = 32/50) of witnessed group]. Mean age was 48 years (range: 27-86); 68% (n = 72/106) were males; and 41% (n = 43/106) had ventricular fibrillation (VF) as initial rhythm. Male gender (OR 0.381; CI 0.156-0.928), PEA (OR 0.175; CI 0.063-0.489, reference VF) and asystole (OR 0.328; CI 0.114-0.944, reference VF) were negatively associated with ROSC. Less than ten minutes duration of CPR (OR 63.628; CI 8.221-429.457) and one co-morbidity status (OR 3.607; CI: 1.26-10.327, reference two or more co-morbidities) were positively associated with ROSC. Overall, 22% (n = 23/106) of enrolled patients left the hospital alive: 34% (n = 17/50) of the witnessed group and 12% (n = 6/56) of the unwitnessed group. CONCLUSION: Out of hospital arrest was associated with dismal survival at hospital discharge, emphasizing the need for development of pre-hospital care services for our country.

Patient expectations from an emergency medical service.

BACKGROUND: Patient expectation survey at the Emergency Medical Services can improve patient satisfaction. A need was established to conduct such a survey in order to recommend its use as a quality improvement tool. METHODS: The study was conducted on patients visiting the Emergency Medical Services, Aga Khan University, Karachi. A questionnaire was used to collect information on the demographic profile, and expectations of patients. The ethical requirements for conducting the study were met. RESULTS: A hundred patients were surveyed. The majority was relatively young, married men and women, well educated and better socio-economically placed. The majority of the patients expected a waiting time and a consultation time of less than 30 minutes and 20 minutes, respectively. The majority of respondents expected and agreed to be examined by a trainee but there were reluctant to be examined by the students. There was an expectation that the consultant will examine patients and not advice the attending team over the phone. The majority of the patients expected intravenous fluid therapy. There was a desire to have patient attendant present during the consultation process. The majority of the patients expected to pay less than three thousand rupees for the visit. An expectation exists for investigations and hospitalization. Involvement of patients in decisions concerning their treatment and written feedback on their visit was expected. CONCLUSIONS: We have documented the need and value of patient expectation survey at the Emergency Medical Services department. The use of such a tool is recommended in order to improve the satisfaction levels of patients visiting such facilities.

Febrile neutropenia: median door-to-needle time - results of an initial audit.

BACKGROUND: Recently, due to inadequacies during immediate management of patients with febrile neutropenia, a new gold standard 'door-to-needle' time of 1 hour for the administration of intravenous antibiotics was introduced. OBJECTIVE: The aim of this audit was to identify whether that target was being met in our emergency department (ED). This is phase 1 of the study which will be followed by identification of barriers to the achievement of the target and recommendations for improvement. MATERIALS AND METHODS: Data were collected from January 2013 to April 2013 of consecutive patients (adult and pediatric age group) who presented to the ED with febrile neutropenia for various underlying causes. Fever was defined as single oral temperature of >38.3°C (101°F) or a temperature of >38.0°C (100.4°F) sustained for more than 1 hour. Neutropenia was defined as absolute neutrophil count <0.5 × 10(9)/l, or expected to fall below that number. Variables analyzed included age, gender, antibiotics administered, underlying diagnosis, day of presentation, and door-to-needle time. RESULTS: During the study period, there were n = 81 patients who presented with febrile neutropenia. There were n = 49 were males and n = 32 were females. There were n = 37 patients in the pediatric age group while rest were adults. Patients most commonly had an underlying hematological malignancy (n = 49). A combination of piperacillin/tazobactam (4.5 g × Q8hrly) and amikacin (750 mg × once daily) was most frequently administered (n = 57) to these patients. The median door-to-needle time was 45 minutes (range ± SD: 10 minutes to 6 hours ± 1 hour 10 minutes). Long delays of over 4 hours occurred in n = 4 patients (all were adults). There were minimal delays observed in pediatric patients due to 'red alert' policy implementation. Long delays occurred on weekdays and weekends, equally. CONCLUSION: The overall median door-to-needle time was 45 minutes, which was in the accepted range. However, delays that occurred demand improvements like introducing 'red alert' policy for adult patients, counseling of staff and residents, identifying potential barriers in achieving the target time along with solutions, and developing hospital-based guidelines on managing patients with neutropenic sepsis.

Prehospital Airway Management in Emergency and Trauma Patients: A Cross-sectional Study of Ambulance Service Providers and Staff in a Low- and Middle-income Country.

BACKGROUND: Prehospital airway management (AM) is the first priority in the care of emergency and trauma victims as it has shown to improve survival in these patients. OBJECTIVE: The aim of this study was to assess training and knowledge of ambulance staff and availability of AM equipment in ambulances of Karachi, Pakistan. METHODS: This cross-sectional study was conducted from June through September 2014. Interviews were conducted with management of six ambulance service providers and 165 ambulance staff. Data from the management included availability of AM equipment in the ambulances, number and designation of staff sent for emergency calls, and AM training of staff. Ambulance staff were assessed for their awareness, knowledge, and training pertaining to AM. RESULTS: All the ambulance services (A through F) had basic equipment for AM but lacked qualified and trained staff. All services had solo drivers (98.3%) for emergency calls; however, Ambulance Service A also had doctors and paramedics. Only 35.7% (59/165) of ambulance staff had awareness regarding AM, out of which 77.9% (46/59) belonged to Ambulance Service A. Of these 59 staff, 81.4% received some form of AM training. Staff with AM awareness, when assessed for knowledge pertaining to AM steps and AM equipment, had a mean score of 4.7/5 and 8.4/12, respectively. CONCLUSION: Even though ambulances are equipped with basic equipment, due to lack of trained staff, these ambulances only serve the mere purpose of transportation. There is a need to train ambulance staff and increase ambulance to staff ratio to improve prehospital AM and patient survival.