Room-temperature DBR-free VCSEL operation on an InGaN/GaN thin-film platform with a monolithic surface grating.

Vertical-cavity surface-emitting lasers (VCSELs) are pivotal in various applications ranging from data communication to sensing technologies. This study introduces a VCSEL design featuring a monolithic top surface high contrast grating (HCG) reflector on a thin-film substrate, aimed at improving lasing performance while reducing fabrication costs by omitting the use of distributed Bragg reflectors (DBRs). We fabricated the proposed VCSEL with the surface grating and characterized its performance through micro-photoluminescence measurements. The laser demonstrated room-temperature lasing at 436.2 nm with a Q factor of 4600 and a lasing threshold of 5.5 kW/cm2 under optical pumping. The implementation of the surface grating reflector was instrumental in facilitating vertical lasing, significantly improving surface reflectivity compared to conventional flat GaN/air interfaces. This innovative design holds significant promise for the development of cost-effective, DBR-free VCSELs, with potential applications extending to photonic integrated circuits and light detection and ranging (LiDAR) systems.

Clinical and pathological characterization of FLNC-related myofibrillar myopathy caused by founder variant c.8129G>A in Hong Kong Chinese.

FLNC-related myofibrillar myopathy could manifest as autosomal dominant late-onset slowly progressive proximal muscle weakness; involvements of cardiac and/or respiratory functions are common. We describe 34 patients in nine families of FLNC-related myofibrillar myopathy in Hong Kong ethnic Chinese diagnosed over the last 12 years, in whom the same pathogenic variant c.8129G>A (p.Trp2710*) was detected. Twenty-six patients were symptomatic when diagnosed; four patients died of pneumonia and/or respiratory failure. Abnormal amorphous material or granulofilamentous masses were detected in half of the cases, with mitochondrial abnormalities noted in two-thirds. We also show by haplotype analysis the founder effect associated with this Hong Kong variant, which might have occurred 42 to 71 generations ago or around Tang and Song dynasties, and underlain a higher incidence of myofibrillar myopathy among Hong Kong Chinese. The late-onset nature and slowly progressive course of the highly penetrant condition could have significant impact on the family members, and an early diagnosis could benefit the whole family. Considering another neighboring founder variant in FLNC in German patients, we advocate development of specific therapies such as chaperone-based or antisense oligonucleotide strategies for this particular type of myopathy.

GaN microdisk with direct coupled waveguide for unidirectional whispering-gallery mode emission.

Microdisks are excellent whispering-gallery mode (WGM) optical resonators, but their emissions are invariably in-plane isotropic due to their circularities and thus difficult to be extracted efficiently. In this work, a waveguide with a width of 0.16 µm directly coupled to a microdisk with a diameter of 10 µm is fabricated on a 0.77 µm thick GaN thin film containing InGaN/GaN multi-quantum wells. This eliminates the need for precision patterning required by evanescent coupling schemes in which coupling gaps of the order of tens of nanometers must be maintained. The fabrication was carried out using nanosphere and nanowire lithography. Non-evanescent coupling of WGMs to the waveguide from the microdisk is successfully demonstrated.

Molecular Identification of Spirometra erinaceieuropaei Tapeworm in Cases of Human Sparganosis, Hong Kong.

Human sparganosis is a foodborne zoonosis endemic in Asia. We report a series of 9 histologically confirmed human sparganosis cases in Hong Kong, China. All parasites were retrospectively identified as Spirometra erinaceieuropaei. Skin and soft tissue swelling was the most common symptom, followed by central nervous system lesions.

Whispering-gallery mode lasing from optically free-standing InGaN microdisks.

Optically pumped multi-mode whispering-gallery mode (WGM) lasing has been observed in optically free-standing InGaN/GaN quantum well microdisks at room temperature. The ∼6.6 µm optically isolated microdisks are patterned by microsphere lithography on GaN thin-films prepared by laser lift-off of the sapphire substrate, enabling superior optical confinement. The modes are determined to be of second order according to simulations. The lasing threshold is found to be ∼9.06 mJ/cm2, with a quality factor Q of ∼770 evaluated from the dominant mode at λ=430.2 nm, and a free space range (FSR) of 3.17 to 2.16 nm, which is mode-dependent.

Safety and Efficacy Comparison of Tenecteplase and Alteplase for Clinically Suspected Large Vessel Occlusion Strokes without Thrombectomy.

INTRODUCTION: Tenecteplase is a thrombolytic with higher fibrin affinity and is potentially better in clot lysis. A higher spontaneous recanalisation rate for large vessel occlusion (LVO) strokes had been shown in comparison studies with alteplase. Results of the LVO studies reflect the composite effect of the thrombolytic and thrombectomy, as patients would be treated by thrombectomy had they not been recanalised by intravenous thrombolysis alone. Thrombectomy is not readily available in many parts of the world. Our study aimed to compare the outcomes of suspected LVO patients treated with tenecteplase versus alteplase only, without the confounding effect of thrombectomy. METHODS: This is a retrospective review. Data of patients given tenecteplase from May 2020 to August 2023 and those given alteplase 0.9 mg/kg from January 2019 to August 2023 were retrieved. Due to fluctuation in supply of tenecteplase during the COVID pandemic, some LVO patients were given alteplase. Patients with anterior circulation, clinically suspected LVO strokes (defined as National Institutes of Health Stroke Scale (NIHSS) score ≥6, plus cortical signs or hyperdense vessel sign), with thrombolysis given within 4.5 h of stroke onset were analysed. Patients with thrombectomy done were excluded. Safety and efficacy outcomes were compared. RESULTS: There were 245 tenecteplase-treated patients treated between May 1, 2020, and August 31, 2023, and 732 patients were treated with alteplase between January 1, 2019, to August 31, 2023. Out of these, 148 tenecteplase patients and 138 alteplase 0.9 mg/kg patients fulfilled the study criteria. The symptomatic intracerebral haemorrhage rate was non-significantly lower in the tenecteplase group (2.1% vs. 5.8%, p = 0.13). There were no significant differences in the rate of ≥8-point NIHSS improvement (23.6% vs. 23.7%, p = 1) or the ≥4-point improvement (40.5% vs. 40.7%, p = 1) at 24 h. At 3 months, 21.6% of tenecteplase patients had good functional outcome (modified Rankin scale [mRS] 0-2), compared to 26.3% in the alteplase group (p = 0.40). CONCLUSION: In this pragmatic study of clinically suspected anterior circulation LVO patients without thrombectomy, outcome solely reflects the effects of tenecteplase. Tenecteplase showed comparable safety and efficacy to alteplase, but the result should be interpreted with caution in view of its small sample size and non-randomised study design.

Mitochondrial diseases in Hong Kong: prevalence, clinical characteristics and genetic landscape.

OBJECTIVE: To determine the prevalence of mitochondrial diseases (MD) in Hong Kong (HK) and to evaluate the clinical characteristics and genetic landscape of MD patients in the region. METHODS: This study retrospectively reviewed the phenotypic and molecular characteristics of MD patients from participating public hospitals in HK between January 1985 to October 2020. Molecularly and/or enzymatically confirmed MD cases of any age were recruited via the Clinical Analysis and Reporting System (CDARS) using relevant keywords and/or International Classification of Disease (ICD) codes under the HK Hospital Authority or through the personal recollection of treating clinicians among the investigators. RESULTS: A total of 119 MD patients were recruited and analyzed in the study. The point prevalence of MD in HK was 1.02 in 100,000 people (95% confidence interval 0.81-1.28 in 100,000). 110 patients had molecularly proven MD and the other nine were diagnosed by OXPHOS enzymology analysis or mitochondrial DNA depletion analysis with unknown molecular basis. Pathogenic variants in the mitochondrial genome (72 patients) were more prevalent than those in the nuclear genome (38 patients) in our cohort. The most commonly involved organ system at disease onset was the neurological system, in which developmental delay, seizures or epilepsy, and stroke-like episodes were the most frequently reported presentations. The mortality rate in our cohort was 37%. CONCLUSION: This study is a territory-wide overview of the clinical and genetic characteristics of MD patients in a Chinese population, providing the first available prevalence rate of MD in Hong Kong. The findings of this study aim to facilitate future in-depth evaluation of MD and lay the foundation to establish a local MD registry.

Ciprofloxacin-induced palatal tremor.

We describe an 84-year-old man with an unusual clinical presentation of palatal tremor in association with ciprofloxacin treatment. The patient had rhythmical movements not only of the soft palate but also of the face and trunk. Complete resolution of the symptoms occurred 2 days after discontinuation of ciprofloxacin and administration of sodium valproate. This is the first reported case of palatal tremor secondary to the use of ciprofloxacin.