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The phase-coherent frequency division of a stabilized optical reference laser to the microwave domain is made possible by optical-frequency combs (OFCs)1,2. OFC-based clockworks3-6 lock one comb tooth to a reference laser, which probes a stable atomic transition, usually through an active servo that increases the complexity of the OFC photonic and electronic integration for fieldable clock applications. Here, we demonstrate that the Kerr nonlinearity enables passive, electronics-free synchronization of a microresonator-based dissipative Kerr soliton (DKS) OFC7 to an externally injected reference laser. We present a theoretical model explaining this Kerr-induced synchronization (KIS), which closely matches experimental results based on a chip-integrated, silicon nitride, micro-ring resonator. Once synchronized, the reference laser captures an OFC tooth, so that tuning its frequency provides direct external control of the OFC repetition rate. We also show that the stability of the repetition rate is linked to that of the reference laser through the expected frequency division factor. Finally, KIS of an octave-spanning DKS exhibits enhancement of the opposite dispersive wave, consistent with the theoretical model, and enables improved self-referencing and access to the OFC carrier-envelope offset frequency. The KIS-mediated enhancements we demonstrate can be directly implemented in integrated optical clocks and chip-scale low-noise microwave generators.
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Spatially resolved omics technologies are transforming our understanding of biological tissues. However, the handling of uni- and multimodal spatial omics datasets remains a challenge owing to large data volumes, heterogeneity of data types and the lack of flexible, spatially aware data structures. Here we introduce SpatialData, a framework that establishes a unified and extensible multiplatform file-format, lazy representation of larger-than-memory data, transformations and alignment to common coordinate systems. SpatialData facilitates spatial annotations and cross-modal aggregation and analysis, the utility of which is illustrated in the context of multiple vignettes, including integrative analysis on a multimodal Xenium and Visium breast cancer study.
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STUDY DESIGN: Cross-sectional study OBJECTIVES: To identify the prevalence of posttraumatic stress disorder (PTSD) among the individuals with traumatic spinal cord injury (TSCI) and to examine the relationships between demographic and clinical characteristics, and PTSD. SETTING: Spinal Injury Rehabilitation Center (SIRC) and Dhulikhel Hospital, Kathmandu University Hospital (DH, KUH), Kavrepalanchowk, Nepal. METHODS: Individuals above 18 years of age with TSCI of at least one month from trauma and admitted to SIRC and DH, KUH from June 2019 to May 2021 were included. The specific stress version of the PostTraumatic Stress Disorder Checklist (PCL), was utilized. To classify the neurological status of TSCI individuals, International Standard for Neurological Classification of Spinal Cord Injury (ISNCSCI) was used. Hierarchical multiple regression analysis between independent variables and normalized PCL score was done to evaluate the predictors of PTSD. RESULTS: Among 163 patients, the overall prevalence of PTSD was 27%, and the mean PCL score was 36 ± 13.9. Factors predictive of PTSD included gender, family type, ethnicity, and literacy rate. No significant association was found between the clinical characteristics and PTSD. CONCLUSIONS: PTSD appears to be considerably prevalent among individuals with TSCI in Nepal. Females, individuals from nuclear families, individuals with lower literacy, and individuals from lower caste are significantly vulnerable to developing PTSD. However, clinical characteristics do not appear to be influential in the development of PTSD.
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Traumatismos de la Médula Espinal , Traumatismos Vertebrales , Trastornos por Estrés Postraumático , Femenino , Humanos , Trastornos por Estrés Postraumático/epidemiología , Estudios Transversales , Nepal/epidemiología , Traumatismos de la Médula Espinal/complicaciones , Traumatismos de la Médula Espinal/epidemiologíaRESUMEN
The Lancet Commission on Global Surgery (LCoGS) recommends using specialist surgical workforce density as one of 6 core indicators for monitoring universal access to safe, affordable surgical and anaesthesia care. Using Nepal as a case study, we explored the capacity of a generalist workforce (led by a family physician or MD general practitioner and non-physician anaesthetist) to enable effective surgical delivery through task-shifting. Using a multiple-methods approach, we retrospectively mapped essential surgical care and the enabling environment for surgery in 39 hospitals in 25 remote districts in Nepal and compared it with LCoGS indicators. All 25 districts performed surgery, 21 performed Caesarean section (CS), and 5 met at least 50% of district CS needs. Generalist surgical teams performed CS, the essential major operation at the district level, and very few laparotomies, but no operative orthopaedics. The density of specialist Surgeon/Anaesthesiologist/Obstetrician (SAO) was 0·4/100,000; that of Generalist teams (gSAO) led by a family physician (MD General Practitioners-MDGP) supported by non-physician anaesthetists was eight times higher at 3·1/100,000. gSAO presence was positively associated with a two-fold increase in CS availability. All surgical rates were well below LCoGS targets. 46% of hospitals had adequate enabling environments for surgery, 28% had functioning anaesthesia machines, and 75% had blood transfusion services. Despite very low SAO density, and often inadequate enabling environment, surgery can be done in remote districts. gSAO teams led by family physicians are providing essential surgery, with CS the commonest major operation. gSAO density is eight times higher than specialists and they can undertake more complex operations than just CS alone. These family physician-led functional teams are providing a pathway to effective surgical coverage in remote Nepal.
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Introduction: Colour Doppler ultrasonography plays an important role in determining the morphological and hemodynamic information of the venous system. This study aimed to find out the prevalence of increased great saphenous vein diameter at the level of the knee among patients with varicose veins in a tertiary care centre. Methods: A descriptive cross-sectional study was carried out in the Department of Radiology at a tertiary care centre from 30 October 2021 to 31 March 2022 after taking ethical approval from the Institutional Review Committee (Reference number: 028-077/078). A convenience sampling technique was used for the study. The study group consisted of patients over 18 years, coming for ultrasonography examination of the lower limb with the clinical symptoms and signs of varicose veins. The great saphenous vein diameter was measured at the level of the medial femoral condyle of the knee using the software in the ultrasonography unit. B mode, colour Doppler and spectral analysis were done. A cut-off value of 5 mm for the diameter of the great saphenous vein was taken to indicate the presence or absence of varicosity and saphenofemoral reflux. Point estimate and 90% Confidence Interval were calculated. Results: Among 72 patients with varicose veins, the diameter of the great saphenous vein was increased in 59 (81.94%) (74.50-89.38, 90% Confidence Interval) patients. Conclusions: The mean diameter of the great saphenous vein in our study was similar when compared to other studies conducted in similar settings. Keywords: saphenous vein; ultrasonography; varicose veins.
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Vena Safena , Várices , Humanos , Estudios Transversales , Vena Safena/diagnóstico por imagen , Centros de Atención Terciaria , Várices/diagnóstico por imagen , Extremidad InferiorRESUMEN
INTRODUCTION: Posterior capsular opacification is a common complication after cataract surgery. Neodynium Yttrium Aluminium Garnet laser capsulotomy is still the preferred treatment for posterior capsular opacification. This study was done to determine the use of Brimonidine eye drop in preventing the rise of intraocular pressure post-Neodynium Yttrium Aluminium Garnet laser capsulotomy. METHODS: A descriptive cross-sectional study was conducted in Lumbini eye institute and research center, Bhairahawa, Nepal, in 200 eyes with posterior capsular opacification using Brimonidine from Feb 1, 2019, to July 30, 2019. The Institutional Review Committee approved the study with approval number 0237. A convenient sampling method was used. Pre-capsulotomy best-corrected visual acuity, slit-lamp examination of the anterior segment, and dilated fundus examination were done. Intraocular pressure was measured with Goldmann Applanation Tonometer. Post capsulotomy patients were evaluated after one hour, two hours, and two weeks for intraocular pressure and any complications. The statistical analysis was done using Statistical Package of Social Sciences version 20.0 statistical analysis software. The descriptive statistical analysis of the study was done after the collection of the data. RESULTS: Mean age of patients at presentation was 61.61±SD 1.09. The mean intraocular pressure following Neodynium Yttrium aluminum garnet laser capsulotomy using brimonidine at 1 hour was 12.73±3.3 mmHg.and two hours was 11.98±3.2 mmHg. The mean energy per pulse was 2.3±SD 0.3 mJ. The mean duration of posterior capsular opacification from cataract surgery was 22.28 weeks. CONCLUSIONS: Neodynium Yttrium Aluminium Garnet laser capsulotomy had lower intraocular pressure after the Brimonidine eye drop procedure. The maximum mean reduction in intraocular pressure was observed after two hours.
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Opacificación Capsular , Láseres de Estado Sólido , Cápsula del Cristalino , Tartrato de Brimonidina/uso terapéutico , Opacificación Capsular/etiología , Opacificación Capsular/cirugía , Estudios Transversales , Humanos , Presión Intraocular , Láseres de Estado Sólido/efectos adversos , Complicaciones Posoperatorias , ItrioRESUMEN
BACKGROUND: Tennis elbow is a common disorder of the upper extremity. It can be treated conservatively in the majority of patients, but some resistant cases eventually can be treated by percutaneous release with good functional outcome. MATERIALS AND METHODS: This non-randomized control trial was conducted at the Department of Orthopaedics Surgery in a tertiary care hospital from July 2015 to June 2016 on 50 patients who underwent percutaneous release of the common extensor origin using an 18 gauge hypodermic needle. These patients did not respond to conservative treatment including rest, nonsteroidal anti-inflammatory drugs (NSAIDS) and local steroid injections. The outcome was graded as Excellent, Good, Fair, and Poor. RESULTS: Fifty patients (50 elbows) were included in the study. Thirty-two patients were female (64%), and 18 were male (36%). The right side was affected in 37 patients (74%) and left side in 13 (26%). The time taken to achieve a completely pain-free elbow ranged from one day to two months (average of 26.2 days). Those who did not achieve a pain-free elbow had a residual pain of 1.5 to six on the visual analogue scale (VAS) (average 2.32). Excellent outcome was noticed in 24 patients (48%); Good result in eight patients (36% ); Fair in four patients (eight percent) and Poor in four patients (eight percent). CONCLUSION: Tennis elbow probably results from the degenerative tear of the common extensor origin, and a percutaneous tenotomy using an 18 gauge hypodermic needle is a simple, safe, patient-friendly, efficient, and easily reproducible method of treating tennis elbow in those who are resistant to conservative treatment, and it can be done as an outpatient procedure.
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BACKGROUND: Displaced Colles' fractures are treated by manipulation and below elbow cast application. Malunion is a common complication, resulting in pain, mid-carpal instability, and post-traumatic arthritis. Fracture stabilization by percutaneous pinning is a simple, minimally invasive technique that helps prevent displacement of the fracture, thereby minimizing complications. This study aims to assess the amount of collapse after closed manipulation and percutaneous pinning with Kirschner wires (K-wires) and its correlation with the functional outcome of the wrist after union. METHODS: A prospective study was conducted from May 2015 to May 2016 in a tertiary orthopedic center. Ninety patients (60 females, 30 males) with an average age of 54.93 years with Type II fractures underwent closed manipulation and percutaneous pinning with crossed K-wires as the primary procedure. Serial radiographs were taken to document the amount of collapse. The functional outcome was assessed using the Cooney Wrist Score. RESULTS: At the final follow-up at six months, the collapse in the mean dorsal angle was 0.94 and mean ulnar variance was 0.51. Functionally, 48 patients (53.33%) had an excellent outcome, 36 patients (40%) had a good outcome, and six patients (6.67%) had a fair outcome. CONCLUSIONS: Displaced Colles' fractures should be reduced and stabilized with percutaneous K-wires to achieve an excellent functional outcome.