Ocular Delivery of Predatory Bacteria with Cryomicroneedles Against Eye Infection

The development of potent antibiotic alternatives with rapid bactericidal properties is of great importance in addressing the current antibiotic crisis. One representative example is the topical delivery of predatory bacteria to treat ocular bacterial infections. However, there is a lack of suitable methods for the delivery of predatory bacteria into ocular tissue. This work introduces cryomicroneedles (cryoMN) for the ocular delivery of predatory Bdellovibrio bacteriovorus (B. bacteriovorus) bacteria. The cryoMN patches are prepared by freezing B. bacteriovorus containing a cryoprotectant medium in a microneedle template. The viability of B. bacteriovorus in cryoMNs remains above 80% as found in long-term storage studies, and they successfully impede the growth of gram-negative bacteria in vitro or in a rodent eye infection model. The infection is significantly relieved by nearly six times through 2.5 days of treatment without substantial effects on the cornea thickness and morphology. This approach represents the safe and efficient delivery of new class of antimicrobial armamentarium to otherwise impermeable ocular surface and opens up new avenues for the treatment of ocular surface disorders.

The Effect of TLR Agonists and Myokines on Secretory Activity of Adipogenically Differentiated MSC Cultures

We studied the effect of bacterial pathogen-associated molecular patterns and myokines on the secretion of adipokines by mesenchymal stem cells (MSC) and products of their adipogenic differentiation. The secretion of adiponectin, adipsin, leptin, and insulin by adipogenically differentiated cell cultures was quantitatively determined using multiplex ELISA. MSC obtained from the stromal vascular fraction of human subcutaneous adipose tissue were shown to secrete a known adipokine adipsin. The ability of white adipocytes to secrete significant amounts of insulin (in vitro) has been shown for the first time. Control cultures of white adipocytes secreted much higher levels of adiponectin, leptin, and insulin when compared to other adipocytes cultures. On the other hand, beige and brown adipocyte cultures secreted more adipsin than white adipocyte cultures. The influence of myokine β-aminoisobutyric acid on the secretion of adipsin in MSC, white, beige, and brown adipocytes was also studied.

EP.TU.465Role of CT scan as initial investigation in colorectal rapid access patients

Background

We looked into CT colonoscopies and CT abdomen and pelvis which were booked as initial investigation in patients referred via the colorectal rapid access pathway. These tests were directly booked following the referral after a nurse led triage.

As per our colorectal straight to test protocol (STT) any patients over the age of 75 or unfit individuals will have a CT colonoscopy (virtual colonoscopy) instead of colonoscopy. CT trunk was used during COVID pandemic as the initial investigation when the aerosol generating procedures were stopped. CT trunks are also the initial investigation as per the STT protocol when patients are referred with suspected abdominal mass, weight loss or abdominal pain.

Methods

Retrospective analysis of prospective electronic data base of colorectal STT referrals from Feb 2020 to end of October 2020.

Results

Conclusion

CT colonoscopies and CT trunks form part of initial diagnostic tool in the colorectal rapid access patients. They are particularly useful in high risk patients who cannot tolerate colonoscopy. These investigations complement the lower GI endoscopy. These scans also identify non-colorectal malignancies and retroperitoneal pathology such as AAA.CT trunks were useful tools during COVID 19 Pandemic.

Unravelling the attributes of novel cyanobacteria Jacksonvillea sp. ISTCYN1 by draft genome sequencing

Filamentous cyanobacteria, Jacksonvillea sp. ISTCYN1 was isolated from agriculture field and cultured in BG-11 medium. This study, report the genome sequence of cyanobacteria Jacksonvillea thatto the best of our knowledgeis the firstgenome sequenceof thisgenus. The 5.7 MB draft genome sequence of this cyanobacterium contains 5134 protein-coding genes. The phylogenetic tree was constructed based on genome and Desertifilum sp. IPPAS B-1220 validated the closest relationship with Jacksonvillea sp. ISTCYN1. The growth of strain ISTCYN1 has been reported in the presence of different types of plastic when used as a sole carbon source. SEM analysis revealed biofilm formation by cyanobacterial strain ISTCYN1 on the surface of high and low-density polyethylene and polypropylene. In the presence of these plastics, EPS production has also been reported by this strain. Whole genome sequence analysis reveals the presence of many genes involved in biofilm formation. The presence of key enzymes responsible for plastic degradation laccase, esterase, lipase, thioesterase, and peroxidase have been predicted in the genome analysis. Genome analysis also provides insight into the genes involved in biotin biosynthetic pathways. Furthermore, the presence of many selenoproteins reveals the selenium acquisition by this cyanobacterium.

Knowledge assessment and outcomes of otolaryngology practice amidst the COVID-19 pandemic in a busy ENT department

INTRODUCTION

Otolaryngology health personnel are at high risk of acquiring COVID-19 disease and, hence, are likely to have high stress levels. This study was designed to evaluate the feedback of otolaryngology healthcare workers in ENT departments who are managing patients in the coronavirus pandemic.

METHODS

A questionnaire focused on all aspects of healthcare delivery was completed by otolaryngology healthcare workers.

RESULTS

The findings, based on statistical analyses, included high stress levels and inadequate disease-related information in these workers.

CONCLUSIONS

Healthcare authorities need to take care of issues related to mental health in healthcare professionals in addition to spreading awareness about safe practices. Further studies are needed to continuously monitor feedback from personnel as the coronavirus pandemic unravels in the future.

Role of postoperative intact serum PTH as an early predictor of severe post-thyroidectomy hypocalcemia: a prospective study

BACKGROUND

Post thyroidectomy hypocalcemia is a major sequel of thyroidectomy and continues to trouble the endocrinologists and the endocrine surgeons as there is no ideal predictive marker of hypocalcemia which has the potential to develop into a life-threatening complication. The role of early serum intact parathormone (iPTH) to predict post thyroidectomy hypocalcemia is becoming useful but the literature is still unclear regarding the optimal time of testing and the optimal cut-off value of serum iPTH.

PATIENTS AND METHODS

This is a prospective cohort study of 111 patients who underwent total thyroidectomy in a tertiary care endocrine surgery referral unit. Serum iPTH was measured after 20 min and 4 h of surgery. Receiver-Operator characteristic Curve (ROC) was used to find out of the best cut-off value of S. iPTH 20 min and 4 h after surgery in predicting hypocalcemia.

RESULTS

Hypocalcemia was noted in 60 (54%) out of 111 subjects who underwent total thyroidectomy. The best cut-off values of Serum iPTH to predict hypocalcemia was found to be 4.28 pmol/l at 20 min post total thyroidectomy with a sensitivity and specificity of 81.7% and 51%, respectively. In addition, patients with malignancy or central lymph nodal dissection were significantly over-represented in the hypocalcemia group with serum iPTH above the threshold level of 4.28 pmol/l. Below the cut off level, parenteral calcium supplementation was required in 23% (17/74) subjects while the rate was only 5.4% (2/37) patients when serum iPTH was above the cut-off level.

CONCLUSIONS

The decline of serum iPTH below a specific level after surgery has predictive value together with other factors strictly related to patient, the thyroid disease itself and surgery. The risk of development of hypocalcemia and consequent need for calcium supplementation should be evaluated by clinical assessment along with serum PTH measurement.

Clinical effectiveness of gasless laparoscopic surgery for abdominal conditions: systematic review and meta-analysis

BACKGROUND

In high-income countries, laparoscopic surgery is the preferred approach for many abdominal conditions. Conventional laparoscopy is a complex intervention that is challenging to adopt and implement in low resource settings. This systematic review and meta-analysis evaluate the clinical effectiveness of gasless laparoscopy compared to conventional laparoscopy with CO₂ pneumoperitoneum and open surgery for general surgery and gynaecological procedures.

METHODS

A search of the MEDLINE, EMBASE, Global Health, AJOL databases and Cochrane Library was performed from inception to January 2021. All randomised (RCTs) and comparative cohort (non-RCTs) studies comparing gasless laparoscopy with open surgery or conventional laparoscopy were included. The primary outcomes were mortality, conversion rates and intraoperative complications.

SECONDARY OUTCOMES

operative times and length of stay. The inverse variance random-effects model was used to synthesise data.

RESULTS

63 studies were included: 41 RCTs and 22 non-RCTs (3,620 patients). No procedure-related deaths were reported in the studies. For gasless vs conventional laparoscopy there was no difference in intraoperative complications for general RR 1.04 [CI 0.45-2.40] or gynaecological surgery RR 0.66 [0.14-3.13]. In the gasless laparoscopy group, the conversion rates for gynaecological surgery were high RR 11.72 [CI 2.26-60.87] when compared to conventional laparoscopy. For gasless vs open surgery, the operative times were longer for gasless surgery in general surgery RCT group MD (mean difference) 10 [CI 0.64, 19.36], but significantly shorter in the gynaecology RCT group MD - 18.74 [CI - 29.23, - 8.26]. For gasless laparoscopy vs open surgery non-RCT, the length of stay was shorter for gasless laparoscopy in general surgery MD - 3.94 [CI - 5.93, - 1.95] and gynaecology MD - 1.75 [CI - 2.64, - 0.86]. Overall GRADE assessment for RCTs and Non-RCTs was very low.

CONCLUSION

Gasless laparoscopy has advantages for selective general and gynaecological procedures and may have a vital role to play in low resource settings.

Integrated hydrochemical and ERT approach for seawater intrusion study in a coastal aquifer: a case study from Jafrabad Town, Gujarat State, India

Hydrochemical and geophysical approach has been adopted to evaluate the seawater intrusion (SWI) in coastal aquifers of Jafrabad Town, Gujarat State, India. Electrical Resistivity Tomography (no. 9) was carried out with spread length of 160-400 m which provided penetration depth of about 23 to 76 m. Very low resistivity zone (0-3 Ω-m range) has been observed in the ERT profiles conducted in the study area. Parameters, namely, TDS, Na, and Cl, have been considered to examine the signature of SWI. The results obtained from ionic ratios, Piper plot, and Chaddha's diagram also confirm the influence of saline water within aquifer. The very low resistivity signature is correlated with the high TDS values in the nearby wells. SWI has been observed up to 9 km from the coast, and it is observed at a depth of 20-22 m in the existing limestone mines near the coast.

O-098 Embryo selection using Artificial Intelligence (AI): Epistemic and ethical considerations

Study question

What are the epistemic and ethical considerations of clinically implementing Artificial Intelligence (AI) algorithms in embryo selection?

Summary answer

AI embryo selection algorithms used to date are “black-box” models with significant epistemic and ethical issues, and there are no trials assessing their clinical effectiveness.

What is known already

The innovation of time-lapse imaging offers the potential to generate vast quantities of data for embryo assessment. Computer Vision allows image data to be analysed using algorithms developed via machine learning which learn and adapt as they are exposed to more data. Most algorithms are developed using neural networks and are uninterpretable (or “black box”). Uninterpretable models are either too complicated to understand or proprietary, in which case comprehension is impossible for outsiders. In the IVF context, these outsiders include doctors, embryologists and patients, which raises ethical questions for its use in embryo selection.

Study design, size, duration

We performed a scoping review of articles evaluating AI for embryo selection in IVF. We considered the epistemic and ethical implications of current approaches.

Participants/materials, setting, methods

We searched Medline, Embase, ClinicalTrials.gov and the EU Clinical Trials Register for full text papers evaluating AI for embryo selection using the following key words: artificial intelligence* OR AI OR neural network* OR machine learning OR support vector machine OR automatic classification AND IVF OR in vitro fertilisation OR embryo*, as well as relevant MeSH and Emtree terms for Medline and Embase respectively.

Main results and the role of chance

We found no trials evaluating clinical effectiveness either published or registered. We found efficacy studies which looked at 2 types of outcomes – accuracy for predicting pregnancy or live birth and agreement with embryologist evaluation. Some algorithms were shown to broadly differentiate well between “good-” and “poor-” quality embryos but not between embryos of similar quality, which is the clinical need. Almost universally, the AI models were opaque (“black box”) in that at least some part of the process was uninterpretable.

“Black box” models are problematic for epistemic and ethical reasons.

Epistemic concerns include information asymmetries between algorithm developers and doctors, embryologists and patients; the risk of biased prediction caused by known and/or unknown confounders during the training process; difficulties in real-time error checking due to limited interpretability; the economics of buying into commercial proprietary models, brittle to variation in the treatment process; and an overall difficulty troubleshooting.

Ethical pitfalls include the risk of misrepresenting patient values; concern for the health and well-being of future children; the risk of disvaluing disability; possible societal implications; and a responsibility gap, in the event of adverse events.

Limitations, reasons for caution

Our search was limited to the two main medical research databases. Although we checked article references for more publications, we were less likely to identify studies that were not indexed in Medline or Embase, especially if they were not cited in studies identified in our search.

Wider implications of the findings

It is premature to implement AI for embryo selection outside of a clinical trial. AI for embryo selection is potentially useful, but must be done carefully and transparently, as the epistemic and ethical issues are significant. We advocate for the use of interpretable AI models to overcome these issues.

Trial registration number

not applicable

MAPbI3 Microrods-Based Photo Resistor Switches: Fabrication and Electrical Characterization

The current work proposed the application of methylammonium lead iodide (MAPbI3) perovskite microrods toward photo resistor switches. A metal-semiconductor-metal (MSM) configuration with a structure of silver-MAPbI3(rods)-silver (Ag/MAPbI3/Ag) based photo-resistor was fabricated. The MAPbI3 microrods were prepared by adopting a facile low-temperature solution process, and then an independent MAPbI3 microrod was employed to the two-terminal device. The morphological and elemental compositional studies of the fabricated MAPbI3 microrods were performed using FESEM and EDS, respectively. The voltage-dependent electrical behavior and electronic conduction mechanisms of the fabricated photo-resistors were studied using current-voltage (I-V) characteristics. Different conduction mechanisms were observed at different voltage ranges in dark and under illumination. In dark conditions, the conduction behavior was dominated by typical trap-controlled charge transport mechanisms within the investigated voltage range. However, under illumination, the carrier transport is dominated by the current photogenerated mechanism. This study could extend the promising application of perovskite microrods in photo-induced resistor switches and beyond.

Sonochemical recovery of uranium from nanosilica-based sorbent and its biohybrid

Use of nanomaterials to remove uranium by adsorption from nuclear wastewater is widely applied, though not much work is focused on the recovery of uranium from the sorbents. The present work reports the recovery of adsorbed uranium from the microstructures of silica nanoparticles (SiO2M) and its functionalized biohybrid (fBHM), synthesized with Streptococcus lactis cells and SiO2M, intensified using ultrasound. Effects of temperature, concentration of leachant (nitric acid), sonic intensity, and operating frequency on the recovery as well as kinetics of recovery were thoroughly studied. A comparison with the silent operation demonstrated five and two fold increase due to the use of ultrasound under optimum conditions in the dissolution from SiO2M and fBHM respectively. Results of the subsequent adsorption studies using both the sorbents after sonochemical desorption have also been presented with an aim of checking the efficacy of reusing the adsorbent back in wastewater treatment. The SiO2M and fBHM adsorbed 69% and 67% of uranium respectively in the second cycle. The adsorption capacity of fBHM was found to reduce from 92% in the first cycle to 67% due to loss of adsorption sites in the acid treatment. Recovery and reuse of both the nuclear material and the sorbent (with some make up or activation) would ensure an effective nuclear remediation technique, catering to UN's Sustainable Development Goals.

Expression map of entry receptors and infectivity factors for pan-coronaviruses in preimplantation and implantation stage human embryos

PURPOSE

To predict if developing human embryos are permissive to multiple coronaviruses.

METHOD

We analyzed publicly available single-cell RNA-seq datasets of human embryos for the known canonical and non-canonical receptors and spike protein cleavage enzymes for multiple coronaviruses like SARS-CoV, SARS-CoV-2, MERS-CoV, hCoV-229E, and hCoV-NL63. We also analyzed the expression of host genes involved in viral replication, host proteins involved in viral endosomal sorting complexes required for transport (ESCRT), genes of host proteins that physically interact with proteins of SARS-CoV-2, and the host genes essential for coronavirus infectivity.

RESULTS

Of the known receptors of SARS viruses, ACE2, BSG, GOLGA7, and ZDHHC5 were expressed in different proportions in the zygote, 4-cell, 8-cell, morula, and blastocysts including the trophectoderm. The MERS-CoV receptor, DPP4, and hCoV-229E receptor, ANPEP, were expressed mainly from the compact morula to the blastocyst stages. Transcripts of the MERS-CoV alternate receptor LGALS1 were detected in most cells at all stages of development. TMPRSS2 transcripts were detected in the epiblast, primitive endoderm, and trophectoderm, while transcripts of the endosomal proteases CTSL, CTSB, and FURIN were expressed in most cells at all stages of development. ACE2 and TMPRSS2 were co-expressed in a proportion of epiblast and trophectoderm cells. The embryonic cells expressed genes involved in ESCRT, viral replication, SARS-CoV-2 interactions, and coronavirus infectivity. The ACE2 and TMPRSS2 co-expressing cells were enriched in genes associated with lipid metabolism, lysosome, peroxisome, and oxidative phosphorylation pathways.

CONCLUSION

Preimplantation and implantation stage human embryos could be permissive to multiple hCoVs.

Kidney transplant surgical director training: Urologists represent a functional alternative to general surgeons

INTRODUCTION

Kidney transplant (KT) directors are general surgeons or urologists. All KT centers must meet established performance standards. However, it has not been established if general surgery and urology led programs have disparate outcomes.

METHODS

Transplant outcomes and donor-recipient characteristics by director training were investigated. Organ Procurement and Transplantation Network (OPTN) directory, program websites were analyzed for surgical director demographics. Scientific Registry of Transplant Recipients (SRTR) 1-year kidney survival and deceased donor (DD) wait-time rankings were evaluated. A retrospective analysis of 142 157 KT recipients from 2010 to 2019 was performed using the United Network for Organ Sharing (UNOS) database.

RESULTS

One hunderd and seventy three (90.6%) KT programs were led by general surgeons. There were no significant differences in gender, ethnicity, region, credentials, or fellowship completion. Recipients undergoing KT with urology led programs were older (P = .002) and had longer wait-times (P < .001). These centers used higher KDPI (.47 vs. .45, P < .001) and higher HLA mismatch (3.92 vs. 3.89, P = .02) kidneys. Urology led centers utilized living donors less frequently (32.1% vs. 35.8%, P < .001) and had longer CIT (15.44 vs. 12.21, P < .001). Both had similar SRTR ranking of 1-year survival and DD wait-time.

CONCLUSION

Most directors were general surgeon. Patient outcomes did not differ by transplant director training. Urologists represent a viable option for KT leadership and recruitment should be encouraged.

508 Conservative Management of Small Bowel Obstruction: A Local Experience

Introduction

Post-operative intra-abdominal adhesions remain the leading cause of small bowel obstruction (SBO) representing one of the main diagnoses warranting emergency laparotomies. The National Audit in Small Bowel Obstruction advocates the use of water-soluble contrast agents (WSCA) as initial management of SBO. We aim to assess the role and outcomes of WSCA and its rate in successfully managing SBO non-operatively.

Method

We conducted a 2-year retrospective analysis including all patients admitted with adhesive SBO. Outcomes of patients who received WSCA were compared to those who hadn’t.

Results

118 patients were included, 27(23%) of which required immediate surgery while 91(77%) were initially managed conservatively. From the latter group, 53(58.2%) received WSCA whilst 38(41.8%) didn’t. Of the group that received WSCA, 36(39.5%) were successfully managed non-operatively, compared to 26(28.5%) that didn’t, this however lacked statistical significance. LOS didn’t differ between these two groups (5 days vs. 5.5 days, p = 0.805). 32% of the patients required eventual surgical intervention needing longer LOS regardless of receiving WSCA (6.6 days vs. 13.6 days p &lt; 0.001).

Conclusions

Adhesive SBO can be managed conservatively in up to two-thirds of patients. WSCA usage has a positive impact but needs further assessment in larger studies.

P15: EVALUATING THE INTERNATIONAL USABILITY OF A LOW-COST LAPAROSCOPIC TRAINER IN LOW- AND HIGH-INCOME SETTINGS

Introduction

Limited access to equipment and trained personnel restrict the adoption of laparoscopic surgery globally. There are a wide range of laparoscopic trainers available; however, most of these are not affordable. We propose an ultra-low-cost laparoscopic trainer (Lap-Pack), designed for portability, ease of assembly and compatibility with smart devices. The study aims to evaluate the usability of Lap-Pack as a training tool in low- and high-income settings.

Method

An international usability study was conducted in India and the UK in 2019. The participants (n=60), consisting of senior surgeons (n=18), junior trainees (n=20) and medical students (n=22), were asked to complete two tasks using Lap-Pack. Participants then scored Lap-Pack in a 25-point questionnaire, including a pre-established Face-Validity Criteria and four major evaluation categories – Usability, Camera, View, Material.

Result

Lap-Pack scored highly in Face-Validity with a combined mean score of 4.63 (95%CI: 4.31, 4.95, p &lt;0.05) of a possible 6. In both cohorts, the Usability and Camera categories scored highest, with combined values respectively of 6.10 (95%CI: 6.01, 6.19, p &lt;0.05) and 6.09 (95%CI: 5.88, 6.31, p &lt;0.05) of a possible 7. For both centres, the highest-scoring individual criteria were its light weight and portability.

Conclusion

Overall, Lap-Pack was received positively by medical students and consultants alike, suggesting it is a suitable device for development of skills as part of a larger laparoscopic training curriculum. Its ease of assembly, portability and versatility show promise of increasing access to training opportunities worldwide.

Take-home message

Lap-Pack is an ultra-low-cost, portable laparoscopic simulator featuring compatibility with smart devices designed to help increase access to laparoscopic training worldwide. An international usability study found medical students, junior trainees and senior surgeons rated its usability and camera features highly, suggesting its employability as a laparoscopic training tool on a global scale.

Prevalence of Loss of Smell and/or Taste and other Otorhinolaryngology Symptoms in COVID-19 Patients

Background Loss of smell and/or taste have been described in COVID-19 patients. Studies have not been conducted to evaluate the loss of smell and/or taste in the context of Nepal. Objective To investigate the prevalence of Ear, Nose and Throat related symptoms and assess smell and taste disorders in laboratory-confirmed SARS-CoV-2 patients. Method This prospective cross-sectional study evaluated patients from September 2020 to March 2021 with preceding COVID-19 diagnosis from a tertiary centre in Kathmandu. COVID-19 positive patients visiting out-patient department, quarantined or admitted were included. Patients were given questionnaire consisting of demographic data, history of smoking and evaluation of presenting symptoms. Loss of smell and taste were subjectively tested and followed up via telephone for ten weeks to evaluate for recovery time and degree of recovery. Result A total of 226 patients participated in the study, 18-92 years old (mean age, 36.77 ± 15.23 years; 53.5% males, 69% non-smokers). Majority of the patients had Myalgia (n = 128, 56.6%) as their presenting symptoms followed by fever (n = 122, 53.9%), loss of smell (n = 117, 51.7%), cough (n = 107, 47.34) and sore throat (n = 102, 45.1%). Loss of sense of smell and taste was reported in 51.8% and 42% respectively. The association between loss of sense of smell and taste was statistically significant (p < .001). All patients had some degree of recovery with 64.1% recovery of smell and 64.2% recovery of taste within 14 days of onset of symptoms. The mean recovery time for sense of smell and taste was 14.34 ± 9.82 days and 15.03 ± 10.06 days, respectively. Conclusion Olfactory and gustatory dysfunctions are cardinal features of COVID-19. They recover spontaneously along with other symptoms within few weeks. The absence of smell or taste in times of pandemic can be suggestive of potential COVID-19 infection and be used as a screening tool for early diagnosis and reduce transmission of the infection.

Filifactor alocis: Recent Insights and Advances

Filifactor alocis, a fastidious Gram-positive obligate anaerobic bacterium, is a newly appreciated member of the periodontal community that is now proposed to be a diagnostic indicator of periodontal disease. Its pathogenic characteristics are highlighted by its ability to survive in the oxidative stress-rich environment of the periodontal pocket and to significantly alter the microbial community dynamics by forming biofilms and interacting with several oral bacteria. Here, we describe the current understanding of F. alocis virulence attributes, such as its comparative resistance to oxidative stress, production of unique proteases and collagenases that can cause structural damage to host cells, and dysregulation of the immune system, which enable this bacterium to colonize, survive, and outcompete other traditional pathogens in the inflammatory environment of the periodontal pocket. Furthermore, we explore the recent advancements and future directions for F. alocis research, including the potential mechanisms for oxidative stress resistance and our evolving understanding of the interactions and mechanisms of bacterial survival inside neutrophils. We also discuss the current genetic tools and challenges involved in manipulating the F. alocis genome for the functional characterization of the putative virulence genes. Collectively, this information will expedite F. alocis research and should lead to the identification of prime targets for the development of novel therapeutics to aid in the control and prevention of periodontal disease.

Ultrasound imaging for the differential diagnosis of periapical lesions of endodontic origin in comparison with histopathology - a systematic review and meta-analysis

BACKGROUND

Differentiating periapical lesions is important for treatment planning and subsequent treatment outcome.

OBJECTIVE

To assess the diagnostic accuracy of ultrasound imaging for the differentiation of periapical lesions in comparison with histopathology.

METHODS

PubMed, Scopus, Embase, Web of Science and ProQuest databases were searched for clinical studies published until June 2020 that evaluated the use of ultrasound (US) imaging for differential diagnosis of periapical lesions and used histopathology as the reference standard. Animal studies, laboratory-based studies, reviews and clinical studies not using a reference standard were excluded. Risk of bias (RoB) assessment was performed using a modified Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. The random effects model was used for quantitative analysis of the data, and the Deeks test was used for calculating publication bias. Quality of evidence was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

Twelve articles were included in the systematic review, out of which ten articles were quantitatively assessed. All the articles had a high RoB and concerns regarding applicability in the patient selection domain. For the index test domain, seven articles had low and the remaining five had unclear RoB and concerns regarding applicability. In the reference standard domain, low RoB and concerns regarding applicability were observed for all the articles. The RoB was low in flow and timing domains in all the articles except for one, where it was high. Summary estimates of sensitivity and specificity of US to diagnose periapical granulomas were 0.94 and 0.98, whereas for periapical cysts it was 0.98 and 0.99, respectively. Area under the curve for diagnosis of both periapical granulomas and periapical cysts was 0.99. All the included articles had inherent publication bias. Quality of evidence using GRADE, for sensitivity, was moderate for periapical granulomas and high for periapical cysts, whereas for specificity, it was high for periapical granulomas and low for periapical cysts.

DISCUSSION

The available evidence is considered to be of low quality due to the observational nature of the studies and inherent publication bias.

CONCLUSION

Although the sensitivity and specificity for differentiating periapical cysts and periapical granulomas using US were high, taking the quality of evidence into consideration, it can serve as an additional tool in differential diagnosis of periapical lesions.

Consequence of aging at Au/HTM/perovskite interface in triple cation 3D and 2D/3D hybrid perovskite solar cells

Perovskite solar cells (PSCs) expressed great potentials for offering a feasible alternative to conventional photovoltaic technologies. 2D/3D hybrid PSCs, where a 2D capping layer is used over the 3D film to avoid the instability issues associated with perovskite film, have been reported with improved stabilities and high power conversion efficiencies (PCE). However, the profound analysis of the PSCs with prolonged operational lifetime still needs to be described further. Heading towards efficient and long-life PSCs, in-depth insight into the complicated degradation processes and charge dynamics occurring at PSCs' interfaces is vital. In particular, the Au/HTM/perovskite interface got a substantial consideration due to the quest for better charge transfer; and this interface is debatably the trickiest to explain and analyze. In this study, multiple characterization techniques were put together to understand thoroughly the processes that occur at the Au/HTM/perovskite interface. Inquest analysis using current-voltage (I-V), electric field induced second harmonic generation (EFISHG), and impedance spectroscopy (IS) was performed. These techniques showed that the degradation at the Au/HTM/perovskite interface significantly contribute to the increase of charge accumulation and change in impedance value of the PSCs, hence resulting in efficiency fading. The 3D and 2D/3D hybrid cells, with PCEs of 18.87% and 20.21%, respectively, were used in this study, and the analysis was performed over the aging time of 5000 h. Our findings propose that the Au/HTM/perovskite interface engineering is exclusively essential for attaining a reliable performance of the PSCs and provides a new perspective towards the stability enhancement for the perovskite-based future emerging photovoltaic technology.

BCG as a game-changer to prevent the infection and severity of COVID-19 pandemic?

The impact of COVID-19 is changing with country wise and depend on universal immunization policies. COVID-19 badly affects countries that did not have universal immunization policies or having them only for the selective population of countries (highly prominent population) like Italy, USA, UK, Netherland, etc. Universal immunization of BCG can provide great protection against the COVID-19 infection because the BCG vaccine gives broad protection against respiratory infections. BCG vaccine induces expressions of the gene that are involved in the antiviral innate immune response against viral infections with long-term maintenance of BCG vaccine-induced cellular immunity. COVID-19 cases are reported very much less in the countries with universal BCG vaccination policies such as India, Afghanistan, Nepal, Bhutan, Bangladesh, Israel, Japan, etc. as compared to without BCG implemented countries such as the USA, Italy, Spain, Canada, UK, etc. BCG vaccine provides protection for 50–60 years of immunization, so the elderly population needs to be revaccinated with BCG. Several countries started clinical trials of the BCG vaccine for health care workers and elderly people. BCG can be uses as a prophylactic treatment until the availability of the COVID-19 vaccine.

A comparative metagenomic study reveals microbial diversity and their role in the biogeochemical cycling of Pangong lake

The environment of a high altitude brackish water lake presents an unprecedented reservoir for the microbial community with adaptability towards surviving stressful conditions. Pangong lake is a high altitude brackish water lake of the Himalayas situated in the eastern part of Ladakh (Indian Tibet), at the height of 4250 m above the sea level. Shotgun metagenomics sequencing of Pangong Lake sediments was performed to examine the taxonomic diversity and functional adaptations of the resident psychrophilic and psychrotolerant microbial communities of the lake (September; a temperature of ±10 °C). Proteobacteria was the most prominent phylum, and Methylophaga, Halomonas, and Marinobacter were mainly abundant at the genus level. Enzyme pathways responsible for methane metabolism, nitrogen metabolism, sulfur reduction, benzoate, and xylene degradation appeared to be complete in the metagenomic dataset. Stress response genes responsible for adaption to pH, cold, salt tolerance, osmotic stress, and oxidative stress were also found in abundance in the metagenome. We compared the Pangong lake metagenome sample to sediments and water samples from three different aquatic habitats, namely saline lake, freshwater lakes and marine ecosystem using MG-RAST server against RefSeq and Subsystem databases. The Pangong lake microbial community contains six unique genera. Regression analysis using metagenome samples suggested that Pangong lake was most closely related to the Trophic South Pacific Ocean (R² = 0.971) and Socompa lake ecosystem (R² = 0.991) at phylum and functional level II, respectively. Our study signifies that the functional metabolic potentiality of Pangong lake is strongly influenced by the taxonomic structure and environmental conditions. We are reporting the metagenome of the sediment sample of the Pangong lake, which unveils the microbial diversity and their functional potential.