Fiber Optic Sensor Coated with Multiple Layers of Hexagonal Boron Nitride Nanosheets (BNNS) for the Detection of Volatile Organic Compounds.

Nowadays, volatile organic compound (VOC) detection is imperative to ensure environmental safety in industry and indoor environments, as well as to monitor human health in medical diagnosis. Gas sensors with the best sensor response, selectivity, and stability are in high demand. Simultaneously, the advancement of nanotechnology facilitates novel nanomaterial-based gas sensors with superior sensor characteristics and low power consumption. Recently, boron nitride, a 2D material, has emerged as an excellent candidate for gas sensing and demonstrated exceptional sensing characteristics for new-generation gas sensing devices. Herein, ultrathin porous boron nitride nanosheets (BNNSs) with large lateral sizes were synthesized using a facile synthesis approach, and their material characteristics were investigated utilizing a variety of analytical techniques, including X-ray diffraction, Fourier transform infrared spectroscopy, ultraviolet spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. A BNNS-coated cladding-modified fiber optic sensor (FOS) probe was prepared and employed for VOC (ammonia, ethanol, and acetone) sensing across concentrations varying from 0 to 300 ppm. The BNNSs-coated FOS demonstrated better selectivity toward 300 ppm ammonia, and specifically annealed BNNSs displayed a maximum sensor response of 55% along with a response/recovery times of 15 s/34 s compared to its counterparts. The superior ammonia sensing performances could be attributed to the formation of ultrathin nanosheets and a porous surface with slit-like features in hexagonal boron nitride.

Non-intubated vs. intubated video-assisted thoracoscopic bullectomy - a retrospective cohort study.

INTRODUCTION: Thoracic surgery procedures evolved enormously over time from open surgery to video assisted thoracoscopic surgery (VATS) and now non-intubated uniportal VATS. At our centre, the initial approach for bullectomy was by uniportal intubated VATS (iVATS) for most cases. Only in mid-2020, in the midst of COVID-19 pandemic, uniportal non-intubated VATS (NiVATS) took precedence. We compared the outcome of bullectomy via iVATS versus NiVATS for a period of 5 years. MATERIALS AND METHODS: We reviewed the medical records of all patients that underwent bullectomy from 1st June 2017 to 31st May 2022. Mann Whitney U-test was completed for all variables. Primary objective was to compare operating time (OT), global operating time (GOT), post-operative length of stay (LOS) and complication rate. RESULTS: A total of 90 bullectomies performed in which 36 were approached via iVATS and 54 NiVATS. It was found that the post-operative LOS, GOT, and OT were significantly shorter in the NiVATS as compared to iVATS. Complication rate between both groups showed no significant difference. CONCLUSION: NiVATS bullectomy demonstrated a safe and reliable alternative surgical approach with superior surgical outcome than iVATS bullectomy.

Thoracic sarcoma case series in Hospital Kuala Lumpur, Malaysia.

Thoracic sarcomas (TS) are rare neoplasms that may present with non-specific pulmonary symptoms. Chest radiographs and computed tomography of the thorax are the investigations of choice, while pre-operative minimally invasive biopsies may not be entirely helpful with the diagnosis. The commonly identified variants of thoracic sarcomas include liposarcomas, leiomyosarcomas and synovial sarcomas. Complete excision of the tumour with clear margins remain the sole definite form of management and there is limited role with adjuvant chemotherapy and radiotherapy. In the present case series, we explore our experience with three patients who presented with TS and the management decisions that was made.

Outcome of surgery of necrotising pneumonia in immunocompromised patients: HKL experience.

Necrotising pneumonia or lung gangrene is a challenging problem and it is diagnosed more often today, especially in tertiary hospitals. It is always a challenge to treat these patients as they are usually immunocompromised and are often ill when the diagnosis is made. We report three immunocompromised patients with necrotising pneumonia who were treated surgically. We share the outcomes of these patients and discuss the management of necrotising pneumonia in the immunocompromised.

Spontaneous massive haemothorax in the peri-partum period of an undiagnosed neurofibromatosis type 1 patient - A surgical perspective.

Acute massive haemothorax is a life-threatening situation, which is often associated with a preceding trauma. However, spontaneous haemothorax is a rare occurrence, especially in pregnancy. Spontaneous haemothorax in the immediate post-partum period secondary to a ruptured intercostal AVM is extremely rare more so in the background of an undiagnosed neurofibromatosis. This is a report of a young lady presenting with pleuritis and breathlessness after the delivery of her 1st child. Her management is discussed.

Mesenteric bones: Intra-abdominal heterotopic ossification.

Intra-abdominal heterotopic ossification usually develops after abdominal surgery and can cause complications such as bowel obstruction and even intestinal perforation. Bisphosphonates, NSAIDs and even local radiation is used as prophylaxis or treatment. Surgeons must consider heterotopic ossification and its complications as a differential when managing complex polytrauma patients with suspicious radiographic densities.

Fiber optic magnetic field sensor using Co doped ZnO nanorods as cladding.

A fiber optic magnetic field sensor is proposed and experimentally demonstrated. Pristine and Co doped ZnO nanorods of different Co concentrations (5, 10, 15 and 20 at%) were synthesized using a hydrothermal method. The synthesized nanorods were subjected to various characterization methods like X-ray diffraction (XRD), optical absorption, scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy, vibrating sample magnetometry and X-ray photoelectron spectroscopy (XPS). XRD and XPS analysis confirms that the Co ions were successfully incorporated into the Zn site of the wurtzite ZnO lattice without altering the structure. The pristine and Co doped ZnO nanorods showed remarkable changes in the M-H loop where the diamagnetic behavior of ZnO changes to paramagnetic when doped with Co. The sensor structure is composed of cladding modified fiber coated with Co doped ZnO nanorods as a sensing material. The modified cladding is proportionally sensitive to the ambient magnetic field because of the magneto-optic effect. Experimental results revealed that the sensor has an operating magnetic field range from 17 mT to 180 mT and shows a maximum sensitivity of ∼18% for 15 at% Co doped ZnO nanorods. The proposed magnetic field sensor would be attractive due to its low cost fabrication, simplicity of the sensor head preparation, high sensitivity and reproducibility.

A dedifferentiated large posterior mediastinal liposarcoma - An incidental finding successfully resected.

This is a case of a posterior mediastinal mass in an asymptomatic gentleman, which was resected successfully and he has been disease free for more than a year of follow up. The histopathology findings happen to be a rare occurrence.

Mediastinal mature teratoma in a child- A case report.

Mediastinal teratoma is an infrequent germ cell tumour and comprises of 1 to 5% of all mediastinal tumours. We report a case of mediastinal mature teratoma in a 12 year old boy who presented to us with persistent non-productive cough, fever and dyspnoea for the past 7 months. Computed tomographic scan of thorax revealed a large anterior mediastinal mass measuring 11.2x9.9x14cm with calcification within. He subsequently underwent a median sternotomy with left subcostal extension (L-incision) and excision of tumour. Histopathology of the tumour revealed a mature cystic teratoma. We would like to report a case of successful surgical management of a large mediastinal mature teratoma in a child.

Abdominal stab wound with inferior vena cava injury: a case report.

No abstract available.

Review of oesophageal atresia and tracheoesophageal fistula in hospital sultanah bahiyah, alor star. Malaysia from january 2000 to december 2009.

Oesophageal atresia (EA) and tracheoesophageal fistula (TEF) is one of the congenital anomaly occurring in the newborns with the incidence of 1 in 2500 births seen worldwide. A retrospective review of newborns admitted to Hospital Sultanah Bahiyah (HSB) from 1st January 2000 to 31st December 2009 was done. The objective was to look at the influence of birth weight, time of surgical intervention, presence of other congenital anomaly and presence of preoperative pneumonia to the immediate outcome (mortality) of the surgery. There were 47 patients with oesophageal atresia, out of which 26 (55%) were males and 21 (45%) females. The distribution of patients by race were 34 Malays (72%), 9 Chinese (19%) and 4 Indians (9%). The birth weight of the babies range from 0.8 kg to 4.0 kg and there was a significant association with the outcome of the surgery (p< 0.05). Most of the babies (20) were operated within 24 hours of presentation but there was no significant association to the outcome. 23 (49%) of them were born with congenital malformation and there was a significant association with the outcome of the surgery (p<0.05). Based on the chest roentgenogram, 20 (43%) of them had pneumonia with significant association with the outcome (p<0.05). The mortality rate is 23% and the causes of death were pneumonia (36%), renal failure (18%), cardiac malformation (18%) and multiple congenital malformations (28%). The outcome of EA and TEF is determined mainly by birth weight, congenital malformations and presence of preoperative pneumonia in HSB.

A community based study on the prevalence and factors affecting smoking in Kampong Jenderam Hilir, Sepang, Selangor.

OBJECTIVES: i) To determine the prevalence of smoking among the community aged 15 and above in Kg. Jenderam Hilir in Sepang District, Selangor state. ii) To determine the relationship between smoking and age, sex, household income and education. iii) To determine the parental and peer influence on smoking in Kg Jenderam Hilir. MATERIALS AND METHODS: A study was conducted in Kg. Jenderam Hilir, Sepang. All residents aged 15 years and above from all the 381 households of Kg. Jenderam Hilir were included in this study. A standardized pre-tested structured questionnaire was used in this study. RESULTS: Out of 894 respondents interviewed 69% were males compared to 3.9% of the females (overall 33.6%) reported to have smoked at least once in his/her lifetime. The difference was statistically significant. The mean duration of smoking was 17.7 years. The age at which smoking was first attempted ranged from 4 years to 51 years with a mean of 18.7 years. The mean initiation age for the males was significantly lower as compared to the mean initiation age for the females. The prevalence of current smokers was significantly higher amongst males (52.8%) as compared to the females (1.4%). The prevalence of smoking among current smokers increased with age (p < 0.01). There was no significant difference in the prevalence of smoking by household income and educational level. The mean number of cigarettes smoked by males was significantly higher than the females (p < 0.05). The mean duration of smoking among current smokers was 20 years. There was a significant difference in the level of addiction to smoking and the duration of smoking (p < 0.05). The high level of addiction increased with the duration of smoking (p < 0.05). Sixty five percent of the current smokers reported to have tried to quit smoking while 26% of ever smokers had reported to quit smoking and remained nonsmokers. The quit ratio was calculated to be 26.0%. The quit ratio was 52.6% among those with college or university education. There was a significant difference in the quit ratio by education level (p < 0.01). There was no significant difference in smokers whose parents were smokers as compared to nonsmokers whose parents were smokers. However, there was a significant association between smoking and peer influence (p < 0.01).

Theory for flow of Casson and Herschel-Bulkley fluids in cone-plate viscometers.

Mathematical models for blood flow in cone-plate viscometer have been considered, by assuming blood as a Casson/Herschel-Bulkley fluid. Three different cases have been analyzed (i) when there is no shearing, (ii) partial shearing and (iii) full shearing. The relationships between the angular velocity and torque have been obtained for the above three cases. By assuming total shearing, the analytical expression for apparent viscosity has been obtained. Variation of apparent viscosity with yield stress, angular velocity, Casson co-efficient of viscosity, consistency index and flow behaviour index has been computed. It is observed that as the angular velocity increases, the apparent viscosity decreases for both fluids. Further, it is found that as the cone angle increases, the apparent viscosity increases. This behaviour of apparent viscosity in cone-plate viscometer is interesting and unexpected and is being reported first time.