Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 124
Filtrar
1.
Semin Ophthalmol ; 39(1): 83-88, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37496206

RESUMO

BACKGROUND: Given limited pre-residency ophthalmology exposure, skill training for PGY-2 ophthalmology residents is essential. However, orientation experiences vary, and skills acquisition is often not measured. OBJECTIVE: A novel video-based orientation curriculum was developed and implemented to standardize and effectively teach ophthalmic examination skills to incoming ophthalmology residents. METHODS: An instructional video library (VL) on ophthalmic exam skills was created in 2020. Prior to any instruction, PGY2s were recorded performing basic ophthalmic exams (BOE) using slit-lamp recording smartphone adapters. After a 2-week orientation involving live teaching, practice, and self-directed library review, ophthalmic exams were again recorded. A 36-point ophthalmic exam skills checklist expanding upon the Ophthalmic Clinical Evaluation Exercise (OCEX) was developed for scoring videos. Residents also completed pre- and post- surveys assessing their comfort with the ophthalmic exam. RESULT: 7 of 11 incoming PGY-2 residents (63.7%) ophthalmology residents participated. Average recorded OCEX score improved from 16.5 ± 5.8 to (p = .0002) to 30.9 ± 2.7. Surveyed resident comfort with the exam increased from 2.4 ± 0.6 to 4.2 ± 0.5 on a 5-point Likert scale (p < .0001). CONCLUSION: Our video library orientation curriculum was effective in rapidly increasing resident comfort and BOE skills. With the launch of the integrated internship model, the VL curriculum may be effective for training ophthalmology PGY1s, medical students and non-ophthalmology providers.


Assuntos
Internato e Residência , Oftalmologia , Humanos , Oftalmologia/educação , Currículo , Inquéritos e Questionários , Competência Clínica
2.
Environ Pollut ; 343: 123140, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38103712

RESUMO

Emerging contaminants in wastewater are one of the growing concerns because of their adverse effects on human health and ecosystems. Adsorption technology offers superior performance due to its cost-effectiveness, stability, recyclability, and reliability in maintaining environmental and health standards for toxic pollutants. Despite extensive research on the use of traditional adsorbents to remove emerging contaminants, their expensiveness, lack of selectivity, and complexity of regeneration remain some of the challenges. Industrial wastes viz. blast furnace slag, red mud, and copper slag can be used to develop efficacious adsorbents for the treatment of emerging contaminants in water. Advantages of the use of such industrial wastes include resource utilization, availability, cost-effectiveness, and waste management. Nevertheless, little is known so far about their application, removal efficacy, adsorption mechanisms, and limitations in the treatment of emerging contaminants. A holistic understanding of the application of such unique industrial waste-derived adsorbents in removing emerging contaminants from water is need of the hour to transform this technology from bench-scale to pilot and large-scale applications. This review investigates different water treatment techniques associated with industrial waste-based adsorbents derived from blast furnace slag, red mud, and copper slag. Besides, this review provides important insights into the growing trends of utilizing such novel types of adsorbents to remove emerging contaminants from water with an emphasis on removal efficacy, controlling measures, adsorption mechanisms, advantages, and limitations. The present timely review brings the current state of knowledge into a single reference which could be a strong platform for future research in understanding the latest advancements, decision making, and financial management related to the treatment of wastewater using industrial waste-based adsorbents.


Assuntos
Poluentes Químicos da Água , Purificação da Água , Humanos , Águas Residuárias , Resíduos Industriais , Cobre , Ecossistema , Reprodutibilidade dos Testes , Adsorção , Purificação da Água/métodos
3.
J Comput Chem ; 45(11): 804-819, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38135467

RESUMO

The inability of p-block elements to participate in π-backbonding restricts them from activating small molecules like CO, H2 , and so forth. However, the development of the main group metallomimetics became a new pathway, where the main-group elements like boron can bind and activate small molecules like CO and H2 . The concept of the frustrated Lewis pair, Boron-Boron multiple bonds, and borylene are previously illustrated. Some of these reported classes of boron species can mimic the jobs of the metal complexes. Hence, we have theoretically studied the binding of CO/N2 molecules at B-center of elusive species like sila/germa boryne stabilized by donor base ligands (cAAC)BE(Me)(L), where E  Si, L  cAACMe , NHCMe , PMe3 , E  Ge, L  cAACMe and (NHCMe )BE(Me)(cAACMe )). The substitutional analogues of (cAACR )BSiR1 (cAAC) and E  P, L  cAACMe ) have been studied by density functional theory (DFT), natural bond orbital, QTAIM calculations and energy decomposition analysis (EDA) coupled with natural orbital for chemical valence (NOCV) analyses. The computed bond dissociation energy and inner stability analyses by the EDA-NOCV method showed that the CO molecule can bind at the B-center of the above-mentioned species due to stronger σ-donor ability while binding of N2 has been theoretically predicted to be weak. The energy barrier for the CO binding is estimated to be 13-14 kcal/mol by transition state calculation. The change of partial triple bond character to single bond nature of the BSi bond and the bending of CBSi bond angle of sila-boryne species are the reason for the activation energy. Our study reveals the ability of such species to bind and activate the CO molecule to mimic the transition metal-containing complexes. We have additionally shown that binding of Fe(CO)4 and Ni(CO)3 is feasible at Si-center after binding of CO at the B-center.

4.
bioRxiv ; 2023 Dec 08.
Artigo em Inglês | MEDLINE | ID: mdl-38105962

RESUMO

The "innate-like" T cell compartment, known as Tinn, represents a diverse group of T cells that straddle the boundary between innate and adaptive immunity, having the ability to mount rapid responses following activation. In mice, this ability is acquired during thymic development. We explored the transcriptional landscape of Tinn compared to conventional T cells (Tconv) in the human thymus and blood using single cell RNA sequencing and flow cytometry. We reveal that in human blood, the majority of Tinn cells, including iNKT, MAIT, and Vδ2+Vγ9+ T cells, share an effector program characterized by the expression of unique chemokine and cytokine receptors, and cytotoxic molecules. This program is driven by specific transcription factors, distinct from those governing Tconv cells. Conversely, only a fraction of thymic Tinn cells displays an effector phenotype, while others share transcriptional features with developing Tconv cells, indicating potential divergent developmental pathways. Unlike the mouse, human Tinn cells do not differentiate into multiple effector subsets but develop a mixed type I/type III effector potential. To conduct a comprehensive cross-species analysis, we constructed a murine Tinn developmental atlas and uncovered additional species-specific distinctions, including the absence of type II Tinn cells in humans, which implies distinct immune regulatory mechanisms across species. The study provides insights into the development and functionality of Tinn cells, emphasizing their role in immune responses and their potential as targets for therapeutic interventions.

5.
Phys Chem Chem Phys ; 25(45): 31396-31409, 2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-37962035

RESUMO

This experimental study aimed to enhance the mechanical and thermal properties of BN (hexagonal boron nitride) nanosheet-reinforced high-density polyethylene by functionalizing its interface. The challenges associated with this nanocomposites are its poor dispersion and weak interface. Accordingly, to improve the load transfer at the interface, BN nanosheets were chemically modified with silane functional groups ((3-aminopropyl)tri-ethoxy silane), making it possible to form covalent bonds between the maleic anhydride-grafted polyethylene and nanosheet. Consequently, three different types of nanocomposite samples were fabricated based on the covalently bonded or non-bonded interface. Two nanocomposite configurations featured a non-bonded interface between the nanofiller and PE matrix (p-BN/PE and (silane functionalized) s-BN/PE). In contrast, the third configuration had a covalently bonded interface (silane-functionalized h-BN + maleic anhydride-grafted PE, i.e., PE-g-BN). According to the zeta potential analysis, the silane-functionalized BN nanosheets were stable suspensions and uniformly dispersed in the polymer matrix. The tensile and flexure strength of the nanocomposites showed over 100% improvement due to the covalently bonded interface. The lamellae structure of PE in the bonded interface samples was responsible for achieving higher mechanical strength in the nanocomposites. Furthermore, the thermal conductivity of the nanocomposites was significantly affected by the type of interfacial bonding, BN wt%, and operating temperature.

6.
Pathol Res Pract ; 245: 154464, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37116364

RESUMO

BACKGROUND: IDH-mutant astrocytomas include CNS WHO grade 2 (A2), grade 3 (A3) and grade 4 (A4), of which A3 and A4 are high-grade. A3 has a heterogenous clinical outcome that cannot be explained entirely by the existing molecular biomarkers. We comprehensively studied the transcriptome profile of A3 to determine clinical significance. METHODS: TCGA mRNA-sequencing data of A3 was analyzed to derive differentially expressed genes (DEG), which were short-listed using various approaches. mRNA expression of the short-listed genes was validated using NanoString platform on a uniformly treated and molecularly characterized A3 cohort. Protein expression of one prognostically significant gene, Iroquois-class homeodomain (IRX1) was assessed by immunohistochemistry and correlated with patient survival and tumor recurrence. IRX1 expression was also studied in different grades of astrocytoma. Since DNA methyltransferase 3 alpha (DNMT3A) influences IRX1 expression, its mutations were evaluated in a subset of tumors. RESULTS: TCGA analysis identified 96 DEG in A3 tumours. 57 genes were short-listed and finally narrowed down to 14 genes. mRNA values of 12/14 genes validated in our cohort. On multiple-variable analysis, IRX1 was the most prognostically relevant gene, with respect to progression free survival of patients. Further, IRX1 immunoexpression was significantly higher in A3 and A4 when compared to A2 and glioblastoma. Higher IRX1 immunoexpression correlated with poor prognosis in patients with A3 tumours. Also, a higher IRX1 expression was associated with DNMT3A mutation. CONCLUSION: Our study identifies IRX1 as a novel biomarker overexpressed in high-grade IDH-mutant astrocytomas with prognostic significance in A3. DNMT3A mutation probably modulates IRX1 expression.


Assuntos
Astrocitoma , Neoplasias Encefálicas , Glioblastoma , Humanos , Neoplasias Encefálicas/patologia , Recidiva Local de Neoplasia , Astrocitoma/genética , Astrocitoma/patologia , Glioblastoma/patologia , Prognóstico , Biomarcadores , Mutação , RNA Mensageiro/genética , Isocitrato Desidrogenase/genética , Fatores de Transcrição/genética , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo
7.
Cureus ; 15(3): e35664, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37012959

RESUMO

Background Out of the many causes of abruptio placentae, the micronutrient association with its occurrence and severity has not been researched extensively till now. We aim to measure the serum levels of homocysteine, folic acid and vitamin B12 in patients with abruptio placentae in the third trimester of pregnancy and compare the levels with those without the complication. We also propose to compare the feto-maternal outcome between the groups. Methods The cross-sectional study was undertaken in 50 pregnant women with abruption before or during delivery and 50 controls with uncomplicated pregnancy over 28 weeks of gestation. Serum levels of homocysteine, folic acid, and vitamin B12 were determined and feto-maternal outcome was compared between the groups Results Mean age of the cases and controls are 26.82 ± 5.5 and 28.82 ± 4.88 years respectively. Obstetric characteristics have significant difference between the groups in terms of gravidity, mode of delivery, timing of delivery, proportion of stillbirths and blood transfusion. The mean concentration of homocysteine and vitamin B12 between the groups also have a significant difference . The serum level of homocysteine is significantly correlated with serum vitamin B12 level (Pearson correlation= -0.601, P=0.000). However, folic acid concentration between the groups remains comparable. Conclusion Hence we conclude that vitamin B12 and homocysteine are significant determinants of abruptio placentae in pregnant women. Supplementation with the vitamin in the high-risk Indian population can avert a number of obstetric complications occurring due to raised homocysteine.

8.
Am J Ophthalmol Case Rep ; 29: 101805, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36714017

RESUMO

Purpose: To describe the use of a tarsoconjunctival pedicle flap for the repair of scleral melt secondary to treatment of conjunctival melanoma. Observation: A 67-year-old woman developed progressive scleromalacia after multiple treatments for an American Joint Committee on Cancer cT2d category conjunctival melanoma. Prior to referral, she underwent synchronous topical chemotherapy (interferon, 5-fluorouracil, mitomycin). Then, incomplete tumor regression led to excision with adjuvant cryotherapy. Lastly, systemic metastasis treated with systemic immunotherapy provided durable remission. However, her multiple treatments (e.g., topical chemotherapy, resection, cryotherapy) were associated with progressive nasal bulbar scleromalacia treated by conjunctival advancement and amniotic membrane grafts. Sclera reinforcement was achieved after a tarsoconjunctival flap was affixed to the eye to cover, and thus vascularize the scleral defect. The tarsoconjunctival flap provided 5 years of tectonic support. Conclusions and Importance: Tarsoconjunctival pedicle flaps can provide scleral integrity for a patient with progressive scleral melting.

9.
J Comput Chem ; 44(1): 43-60, 2023 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-36169176

RESUMO

The factors/structural features which are responsible for the binding, activation and reduction of N2 to NH3 by FeMoco of nitrogenase have not been completely understood well. Several relevant model complexes by Holland et al. and Peters et al. have been synthesized, characterized and studied by theoretical calculations. For a matter of fact, those complexes are much different than real active N2 -binding Fe-sites of FeMoco, which possesses a central C(4-) ion having an eight valence electrons as an µ6 -bridge. Here, a series of [(S3 C(0))Fe(II/I/0)-N2 ]n- complexes in different charged/spin states containing a coordinated σ- and π-donor C(0)-atom which possesses eight outer shell electrons [carbone, (Ph3 P)2 C(0); Ph3 P→C(0)←PPh3 ] and three S-donor sites (i.e. - S-Ar), have been studied by DFT, QTAIM, and EDA-NOCV calculations. The effect of the weak field ligand on Fe-centres and the subsequent N2 -binding has been studied by EDA-NOCV analysis. The role of the oxidation state of Fe and N2 -binding in different charged and spin states of the complex have been investigated by EDA-NOCV analyses. The intrinsic interaction energies of the Fe-N2 bond are in the range from -42/-35 to -67 kcal/mol in their corresponding ground states. The S3 C(0) donor set is argued here to be closer to the actual coordination environment of one of the six Fe-centres of nitrogenase. In comparison, the captivating model complexes reported by Holland et al. and Peter et al. possess a stronger π-acceptor C-ring (S2 Cring donor, π-C donor) and stronger donor set like CP3 (σ-C donor) ligands, respectively.


Assuntos
Carbono , Nitrogenase , Nitrogenase/química , Carbono/química , Nitrogênio/química , Ligantes , Ferro/química
10.
Ophthalmic Physiol Opt ; 43(1): 132-140, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36271902

RESUMO

PURPOSE: We developed a clip-on light tracker (MyLyt) for estimating light exposure in real time. This study aimed at validating and investigating the feasibility of using MyLyt in children and adults. METHOD: The study was conducted in two phases. Phase 1 involved validation against a factory-calibrated digital lux meter in three separate conditions: controlled environmental set-up, outdoors and indoors where intra-test (two measurements by the same tracker), inter-test (measurements among trackers) and inter-device (MyLyt tracker and lux meter) validations were conducted. Phase 2 involved a feasibility study where MyLyt was used in a real-world setting by 21 adults and 8 children. Participants were asked to log their real-time movements in an 'activity diary', which were correlated with the lux levels measured by the tracker. RESULTS: A strong positive correlation and non-significant difference in the recorded mean illuminance levels were observed during intra-test (inter-class correlation: 1.00, p = 0.99), inter-test (0.91-1.00, p > 0.15) and inter-device (0.91-1.00, p > 0.56) validation in all three testing conditions (p > 0.49), except the indoor location. While the lux level measured by MyLyt was significantly higher than that of the lux meter (p < 0.01) in the indoor locations, differences were minimal and clinically insignificant. A Bland-Altman plot showed a minimal mean difference (95% limits of agreement) between the MyLyt tracker and lux meter in all three conditions (controlled environmental set-up: 641 [-949, 2230], outdoor: 74 [-2772, 2920] and indoor: -35 [-151, 80] lux). Phase 2 validation showed an expected illuminance level against the corresponding location with high sensitivity (97.8%) and specificity (99%) to accurately differentiate between outdoor and indoor locations. CONCLUSION: The MyLyt tracker showed good repeatability, strong correlation and comparable values with the lux meter in the three tested conditions, making it suitable for tracking light exposure patterns for both research and clinical purposes.


Assuntos
Criança , Humanos
12.
ACS Omega ; 7(35): 31577-31590, 2022 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-36092593

RESUMO

The FeVco cofactor of nitrogenase (VFe7S8(CO3)C) is an alternative in the molybdenum (Mo)-deficient free soil living azotobacter vinelandii. The rate of N2 reduction to NH3 by FeVco is a few times higher than that by FeMoco (MoFe7S9C) at low temperature. It provides a N source in the form of ammonium ions to the soil. This biochemical NH3 synthesis is an alternative to the industrial energy-demanding production of NH3 by the Haber-Bosch process. The role of vanadium has not been clearly understood yet, which has led chemists to come up with several stable V-N2 complexes which have been isolated and characterized in the laboratory over the past three decades. Herein, we report the EDA-NOCV analyses of dinitrogen-bonded stable complexes V(III/I)-N2 (1-4) to provide deeper insights into the fundamental bonding aspects of V-N2 bond, showing the interacting orbitals and corresponding pairwise orbital interaction energies (ΔE orb(n)). The computed intrinsic interaction energy (ΔE int) of V-N2-V bonds is significantly higher than those of the previously reported Fe-N2-Fe bonds. Covalent interaction energy (ΔE orb) is more than double the electrostatic interaction energy (ΔE elstat) of V-N2-V bonds. ΔE int values of V-N2-V bonds are in the range of -172 to -204 kcal/mol. The V → N2 ← V π-backdonation is four times stronger than V ← N2 → V σ-donation. V-N2 bonds are much more covalent in nature than Fe-N2 bonds.

13.
Am J Clin Pathol ; 158(4): 521-529, 2022 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-35913110

RESUMO

OBJECTIVES: We aimed to evaluate the expression pattern of chitinase 3-like 2 (CHI3L2) in the tumor core and peritumoral brain zone (PBZ) of newly diagnosed glioblastoma (GBM) in recurrent tumors and its association with patient prognosis. METHODS: The study was conducted on three sample sets derived from different patient cohorts. Messenger RNA (mRNA) expression of CHI3L2 in the tumor core and PBZ (n = 34) compared with control (n = 20) tissues was studied by quantitative polymerase chain reaction in sample set 1. Sample set 2 included 19 paired, primary-recurrent GBM tissues. Sample set 3 comprised 82 GBM tissues of patients with treatment and follow-up information. Immunohistochemistry (IHC) was performed on all three sample sets. RESULTS: mRNA expression of CHI3L2 was significantly higher in the tumor core and PBZ compared with control (P < .0001). By IHC, CHI3L2 showed strong cytoplasmic staining in tumor cells. Recurrent tumors had a higher expression of CHI3L2 compared with primary tumors (P = .007). Survival analysis showed CHI3L2 expression was associated with shorter overall survival (P = .034) and progression-free survival (P = .010), which was in line with The Cancer Genome Atlas cohort (P = .043). CONCLUSIONS: High expression of CHI3L2 in the tumor core and PBZ, as well as its association with tumor recurrence and poor patient prognosis, suggests it might be contributing to tumor spread and recurrence.


Assuntos
Neoplasias Encefálicas , Quitinases , Glioblastoma , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/genética , Quitinases/genética , Glioblastoma/diagnóstico , Glioblastoma/genética , Humanos , Recidiva Local de Neoplasia/metabolismo , Prognóstico , RNA Mensageiro
14.
Oncoimmunology ; 11(1): 2109861, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35979386

RESUMO

Tyrosine kinase inhibitors (TKIs) have dramatically improved the survival in chronic myeloid leukemia (CML), but residual disease typically persists even after prolonged treatment. Several lines of evidence suggest that TKIs administered to CML patients upregulate interferon γ (IFNγ) production, which may counteract the anti-tumorigenic effects of the therapy. We now show that activated T cell-conditioned medium (TCM) enhanced proliferation and counteracted imatinib-induced apoptosis of CML cells, and addition of a neutralizing anti-IFNγ antibody at least partially inhibited the anti-apoptotic effect. Likewise, recombinant IFNγ also reduced imatinib-induced apoptosis of CML cells. This anti-apoptotic effect of IFNγ was independent of alternative IFNγ signaling pathways, but could be notably diminished by STAT1-knockdown. Furthermore, IFNγ upregulated the expression of several anti-apoptotic proteins, including MCL1, PARP9, and PARP14, both in untreated and imatinib-treated primary human CD34+ CML stem/progenitor cells. Our results suggest that activated T cells in imatinib-treated CML patients can directly rescue CML cells from imatinib-induced apoptosis at least partially through the secretion of IFNγ, which exerts a rapid, STAT1-dependent anti-apoptotic effect potentially through the simultaneous upregulation of several key hematopoietic survival factors. These mechanisms may have a major clinical impact, when targeting residual leukemic stem/progenitor cells in CML.


Assuntos
Interferon gama , Leucemia Mielogênica Crônica BCR-ABL Positiva , Antígenos CD34/metabolismo , Antígenos CD34/farmacologia , Apoptose , Linhagem Celular Tumoral , Humanos , Mesilato de Imatinib/farmacologia , Mesilato de Imatinib/uso terapêutico , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/metabolismo , Células-Tronco/metabolismo , Regulação para Cima
15.
J Environ Manage ; 316: 115259, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35658251

RESUMO

Nature-based solutions or Green infrastructure (GI) used for managing stormwater pollution are growing in popularity across the globe. Stormwater GI models are important tools to inform the planning of these systems (type, design, size), in the most efficient and cost-effective manner. MUSIC, an example of such a tool, uses regression and first order decay models. Studies validating MUSIC model performance are, however, scarce, hindering future model development and transferability of the model for systems operating under different design and climatic conditions. To close this gap, this paper evaluates MUSIC for a field scale bioretention system, stormwater wetland and vegetated swale operating under Singapore tropical climate. The treatment modules were able to simulate outflows and effluent pollutant concentrations reasonably well for cumulative event volumes (mostly within ±25%) and cumulative TP and TN loads (within ±30%). Outflow TSS loads were significantly under-estimated as a result of greater variability in measured TSS concentrations across events. The findings indicate that simple empirical models such as MUSIC can be transferred to different regions provided that management decisions are based on long-term modelling efforts. The modules generally simulated the outflow hydrographs and pollutographs of the different inflow and drying/wetting conditions relatively poorly.


Assuntos
Chuva , Qualidade da Água , Singapura , Movimentos da Água
17.
Cureus ; 14(4): e23792, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35530863

RESUMO

A 20-year-old female patient with a family history significant for Peutz-Jeghers syndrome presented to the hospital multiple times with complaints of abdominal pain. On the initial visit to the hospital, the patient underwent small bowel resection for small bowel obstruction secondary to intussusception, following which she visited the hospital again one year later for similar complaints and underwent reduction of multiple points of intussusception of the small bowel without any resection of the same. Eventually, the patient underwent resection of the small bowel for the second time, along with tumor resections. The importance of follow-up in patients with Peutz-Jeghers is particularly essential, in part, because it is vital to monitor the tumors, their size, and number to prevent surgical intestinal complications, anemia, and also to eventually monitor for carcinomatous changes.

18.
ANZ J Surg ; 92(10): 2492-2499, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35451174

RESUMO

BACKGROUND: Mesh is frequently utilized intraoperatively for the repair of groin hernias. However, patients may request non-mesh hernia repairs owing to adverse events reported in other mesh procedures. To inform surgical safety, this study aimed to compare postoperative complications between mesh and non-mesh groin hernia repairs and identify other operative and patient-related risk factors associated with poor postoperative outcomes. METHODS: Ovid MEDLINE and grey literature were searched to 9 June 2021 for studies comparing mesh to non-mesh techniques for primary groin hernia repair. Outcomes of interest were postoperative complications, recurrence of hernia, pain and risk factors associated with poorer surgical outcomes. Methodological quality was appraised using the AMSTAR 2 tool. RESULTS: The systematic search returned 4268 results, which included seven systematic reviews and five registry analyses. Mesh repair techniques resulted in lower hernia recurrence rates, with no difference in chronic pain, seroma, haematoma or wound infection, compared to non-mesh techniques. Risk factors associated with increased risk of hernia recurrence were increased body mass index (BMI), positive smoking status and direct hernia. These were independent of surgical technique. Patients under 40 years of age were at increased risk of postoperative pain. CONCLUSIONS: Surgical repair of primary groin hernias using mesh achieves lower recurrence rates, with no difference in safety outcomes, compared with non-mesh repairs. Additional risk factors associated with increased recurrence include increased BMI, history of smoking and hernia subtype.


Assuntos
Hérnia Inguinal , Herniorrafia , Virilha/cirurgia , Hérnia Inguinal/complicações , Herniorrafia/efeitos adversos , Herniorrafia/métodos , Humanos , Complicações Pós-Operatórias/etiologia , Recidiva , Telas Cirúrgicas/efeitos adversos
19.
Sci Total Environ ; 831: 154911, 2022 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-35364143

RESUMO

Stormwater biofiltration systems (also known as biofilters, bioretention, rain gardens) are engineered nature-based solutions, which help mitigate aquatic nitrogen pollution arising from storm runoff. These systems are being increasingly used in a range of climates across the world. A decline in treatment performance is frequently observed in cold weather conditions. While plant species comprise an important design factor influencing system performance, the effect of temperature on the fate of dissolved nitrogen forms, namely ammonium (NH4+) and nitrate (NO3-), in the presence of different plant species in these systems remains unclear. A large scale laboratory experiment was undertaken that measured potential rates of nitrification, denitrification and dissimilatory nitrate reduction to ammonium (DNRA) as well as the microbial community structure to investigate nitrogen fate and hence removal under two different temperature conditions (2 °C and 15 °C) in the presence of four distinct plant species. The results indicate that lower nitrification rates (reduced by a factor of 4) coupled with potential media NH4+ desorption could be contributing to reduced NH4+ removal during cold conditions. Planting with species exhibiting good nutrient uptake capacity can reduce the extent of this performance decline. While NO3- reduction generally remains problematic during cold weather (<0 to 55% reduction), which may not be significantly different from warmer periods, the study demonstrated that the denitrification potential and gene abundance (nap, nar, NirS, norB, nosZ) to be higher than those of nitrification (amoA). Denitrification may not proceeding at optimal rates due to lack of conducive environmental conditions. Nitrogen transformation via DNRA was found to be relatively insignificant. Future studies should investigate the potential of employing cold-resilient plant species to maintain both NH4+ and NO3- removal in cold weather conditions.


Assuntos
Compostos de Amônio , Desnitrificação , Nitratos , Nitrogênio , Óxidos de Nitrogênio , Plantas , Temperatura
20.
RSC Adv ; 12(7): 4081-4093, 2022 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-35425464

RESUMO

Recently, dinitrogen (N2) binding and its activation have been achieved by non-metal compounds like intermediate cAAC-borylene as (cAAC)2(B-Dur)2(N2) [cAAC = cyclic alkyl(amino) carbene; Dur = aryl group, 2,3,5,6-tetramethylphenyl; B-Dur = borylene]. It has attracted a lot of scientific attention from different research areas because of its future prospects as a potent species towards the metal free reduction of N2 into ammonia (NH3) under mild conditions. Two (cAAC)(B-Dur) units, each of which possesses six valence electrons around the B-centre, are shown to accept σ-donations from the N2 ligand (B ← N2). Two B-Dur further provide π-backdonations (B → N2) to a central N2 ligand to strengthen the B-N2-B bond, providing maximum stability to the compound (cAAC)2(B-Dur)2(N2) since the summation of each pair wise interaction accounted for the total stabilization energy of the molecule. (cAAC)(B-Dur) unit is isolobal to cAAC-E (E = Si, Ge) fragment. Herein, we report on the stability and bonding of cAAC-E bonded N2-complex (cAAC-E)2(N2) (1-2; Si, Ge) by NBO, QTAIM and EDA-NOCV analyses (EDA-NOCV = energy decomposition analysis coupled with natural orbital for chemical valence; QTAIM = quantum theory of atoms in molecule). Our calculation suggested that syntheses of elusive (cAAC-E)2(N2) (1-2; Si, Ge) species may be possible with cAAC ligands having bulky substitutions adjacent to the CcAAC atom by preventing the homo-dimerization of two (cAAC)(E) units which can lead to the formation of (cAAC-E)2. The formation of E[double bond, length as m-dash]E bond is thermodynamically more favourable (E = Si, Ge) over binding energy of N2 inbetween two cAAC-E units.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA