Soft X-ray and ENA Imaging of the Earth's Dayside Magnetosphere.

The LEXI and SMILE missions will provide soft X-ray images of the Earth's magnetosheath and cusps after their anticipated launch in 2023 and 2024, respectively. The IBEX mission showed the potential of an Energetic Neutral Atom (ENA) instrument to image dayside magnetosheath and cusps, albeit over the long hours required to raster an image with a single pixel imager. Thus, it is timely to discuss the two imaging techniques and relevant science topics. We simulate soft X-ray and low-ENA images that might be observed by a virtual spacecraft during two interesting solar wind scenarios: a southward turning of the interplanetary magnetic field and a sudden enhancement of the solar wind dynamic pressure. We employ the OpenGGCM global magnetohydrodynamics model and a simple exospheric neutral density model for these calculations. Both the magnetosheath and the cusps generate strong soft X-rays and ENA signals that can be used to extract the locations and motions of the bow shock and magnetopause. Magnetopause erosion corresponds closely to the enhancement of dayside reconnection rate obtained from the OpenGGCM model, indicating that images can be used to understand global-scale magnetopause reconnection. When dayside imagers are installed with high-ENA inner-magnetosphere and FUV/UV aurora imagers, we can trace the solar wind energy flow from the bow shock to the magnetosphere and then to the ionosphere in a self-standing manner without relying upon other observatories. Soft X-ray and/or ENA imagers can also unveil the dayside exosphere density structure and its response to space weather.

Metformin as a radiosensitiser for pelvic malignancy: A systematic review of the literature.

BACKGROUND: The treatment of pelvic malignancies has continued to improve over recent years, with neoadjuvant radiotherapy often considered the gold standard to downstage disease. Radiosensitisers are routinely employed in an attempt to improve response of cancers to radiotherapy. Previous preclinical evidence has suggested a role for metformin, a commonly used drug for type 2 diabetes. METHOD: A literature search was performed for published full text articles using the PubMed, Cochrane and Scopus databases using the search criteria string 'Metformin' AND ('Radiosensitivity' OR 'radiosensitising' OR 'radiosensitising'). Additional papers were detected by scanning the references of relevant papers. Data were extracted from each study by two authors onto a dedicated proforma. The review was registered on the PROSPERO database (ID: CRD42020199066). RESULTS: A total of 242 papers were identified, 11 of which were included in this review; an additional 5 papers were obtained from reference searches. Metformin has been demonstrated to reduce cell-viability post-radiotherapy in both rectal and prostate cancer cell lines, with an enhanced effect in tumours with a p53 mutation and increased apoptosis post-radiotherapy for cervical cancer. Clinical trials demonstrate improved tumour and nodal downstaging and pCR rates for rectal cancer using metformin as a radiosensitiser. CONCLUSION: With an increasing understanding of the underlying mechanism of the effects on metformin prospective studies are required to assess the effect of routine use on cancer related outcomes. Progressive future studies may be better served by the use of predictive biomarker guided treatment to enable identification of the appropriate cohort to target.

COVID-19: Initial experience of an international group of hand surgeons.

The emergence of the COVID-19 pandemic has severely affected medical treatment protocols throughout the world. While the pandemic does not affect hand surgeons at first glance, they have a role to play. The purpose of this study was to describe the different measures that have been put in place in response to the COVID-19 pandemic by hand surgeons throughout the world. The survey comprised 47 surgeons working in 34 countries who responded to an online questionnaire. We found that the protocols varied in terms of visitors, health professionals in the operating room, patient waiting areas, wards and emergency rooms. Based on these preliminary findings, an international consensus on hand surgery practices for the current viral pandemic, and future ones, needs to be built rapidly.

General hospital admission rates in people diagnosed with personality disorder.

OBJECTIVE: To determine the frequency of all-cause general hospital admissions for individuals with personality disorder (PD) in a large clinical population using linked secondary mental healthcare and hospitalisation data. METHOD: A retrospective cohort study, using anonymised electronic mental health records from South London and Maudsley NHS Foundation Trust (SLaM), linked to Hospital Episodes Statistics in England. People with PD aged 15 years or older, receiving care within SLaM between April 2007 and March 2013, were identified and compared to residents from the local catchment area. Standardised admission ratios (SARs) were calculated for all major categories of causes of general hospital admission for this defined group, with local residents in 2011 UK Census as the standard population. RESULTS: For the 7677 people identified with PD, SAR for all causes of admission was 2.75 (95% CI: 2.70, 2.81). Both men and women with PD had increased SARs across multiple ICD-10 categories, including circulatory, respiratory, digestive, nervous, and musculoskeletal system disorders and endocrine, blood and infectious disorders. Sensitivity analysis (removing the impact of repeated admissions by same individual for same diagnosis in the same year) yielded similar findings. CONCLUSIONS: By comparison with members of the general population, individuals with a diagnosis of personality disorder are at significantly higher risk of hospital admission resulting from a wide range of physical health problems.

Alzheimer's disease: insights for risk evaluation and prevention in the Chinese population and the need for a comprehensive programme in Hong Kong/China.

With the ageing of the global population, China is projected to be impacted significantly by the rising number of patients with Alzheimer's disease (AD). A cure for AD is not yet available, so society should be prepared for an increasing AD-related burden. In this review, we examine this impending problem and provide overviews on (a) the magnitude of the problem of AD in Hong Kong/China in the near future; (b) the genetic and lifestyle risk factors that contribute to AD; (c) current diagnostic approaches and the potential of newly discovered genetic biomarkers for early detection; (d) medications, non-pharmacological interventions, and possible preventive measures; and (e) the need for social and psychological care from the community. In Hong Kong, primary care and AD-related support for at-risk individuals, patients, and caregivers are inadequate. A joint effort from the medical community, government, universities, non-governmental organisations/charities, and industry should initiate the development of a long-term programme for AD. Finally, we outline recommendations for the relevant parties to consider.

Use of the embedded peritoneal dialysis catheter.

Introduction The use of embedded peritoneal dialysis (PD) catheters is purported to offer numerous benefits over standard placement. However, the optimum period of embedment and the effect of prolonged embedment on subsequent catheter function remain unclear. Methods This retrospective observational study looked at adult patients undergoing embedded PD catheter insertion in a large tertiary referral centre in the UK. Possible predictors for catheter non-function at externalisation were investigated. These included patient factors (age, sex, diabetic status, body mass index, ethnicity, smoking status, previous surgery, estimated glomerular filtration rate), procedural factors (modality of surgery, concurrent surgical procedure), duration of catheter embedment and catheter damage at externalisation. Outcomes examined were proportion of catheters functioning after externalisation, futile placement rate, surgical reintervention rate, infectious complication rate and proportion of externalised catheters lost owing to malfunction. Results Sixty-six catheters were embedded and two-thirds (n=47, 63.6%) were externalised after a median embedment period of 39.4 weeks. Of these, 25 (53.2%) functioned on externalisation. Fourteen (63.6%) of the 22 non-functioning catheters were salvaged. The overall utilisation of PD was 34/47 (72.3%) and the futile placement rate was 12.1%. Over half of the externalised catheters (n=27, 57.4%) were lost directly as a result of catheter related complications, with a median survival time of 39.4 weeks. In adjusted analysis, increasing embedment duration was significantly predictive of catheter non-function at externalisation (adjusted odds ratio: 0.957, 95% confidence interval [CI]: 0.929-0.985, p=0.003) while subsequent catheter loss was highly dependent on catheter function at externalisation (hazard ratio: 0.258, 95% CI: 0.112-0.594, p=0.001). Conclusions Prolonged embedment of PD catheters is associated with a significantly higher likelihood of catheter dysfunction following externalisation, which is in turn associated with subsequent catheter loss. We have discontinued the use of this technique in our unit.

Including Kinetic Ion Effects in the Coupled Global Ionospheric Outflow Solution.

We present a new expansion of the Polar Wind Outflow Model (PWOM) to include kinetic ions using the Particle-in-Cell (PIC) approach with Monte Carlo collisions. This implementation uses the original hydrodynamic solution at low altitudes for efficiency, and couples to the kinetic solution at higher altitudes to account for kinetic effects important for ionospheric outflow. The modeling approach also includes wave-particle interactions, suprathermal electrons, and an hybrid parallel computing approach combining shared and distributed memory paralellization. The resulting model is thus a comprehensive, global, model of ionospheric outflow that can be run efficiently on large supercomputing clusters. We demonstrate the model's capability to study a range of problems starting with the comparison of kinetic and hydrodynamic solutions along a single field line in the sunlit polar cap, and progressing to the altitude evolution of the ion conic distribution in the cusp region. The interplay between convection and the cusp on the global outflow solution is also examined. Finally, we demonstrate the impact of these new model features on the magnetosphere by presenting the first 2-way coupled ionospheric outflow-magnetosphere calculation including kinetic ion effects.

A novel microwave sensor to detect specific biomarkers in human cerebrospinal fluid and their relationship to cellular ischemia during thoracoabdominal aortic aneurysm repair.

Thoraco-abdominal aneurysms (TAAA) represents a particularly lethal vascular disease that without surgical repair carries a dismal prognosis. However, there is an inherent risk from surgical repair of spinal cord ischaemia that can result in paraplegia. One method of reducing this risk is cerebrospinal fluid (CSF) drainage. We believe that the CSF contains clinically significant biomarkers that can indicate impending spinal cord ischaemia. This work therefore presents a novel measurement method for proteins, namely albumin, as a precursor to further work in this area. The work uses an interdigitated electrode (IDE) sensor and shows that it is capable of detecting various concentrations of albumin (from 0 to 100 g/L) with a high degree of repeatability at 200 MHz (R(2) = 0.991) and 4 GHz (R(2) = 0.975).

A less invasive distal osteotomy of the radius for malunited dorsally displaced extra-articular fractures.

A less invasive corrective osteotomy for symptomatic post-traumatic deformity of the distal radius was done in 12 patients. They were followed up for an average of 3.7 years. The indications for correction were based on the patients' level of activities, pain, functional limitations, loss of grip strength or deformity occurring with an extra-articular rotational malunion of the distal end of the radius. The procedure included a dorsal open wedge osteotomy through a dorsal incision in which the fulcrum of rotation, or hinge, was located at the palmar cortex, and stabilized with an extra- and intramedullary fixed angle device. The bone defect was replaced with autologous morsellized iliac bone graft. The final outcome was graded as very good in eight patients, good in two and fair in two. Level of evidence: IV.

An apical left ventricular aneurysm rupture presenting as left breast mass 11 years after surgical repair.

Left ventricular (LV) pseudoaneurysm is a rare entity and, consequently, there is limited knowledge of the condition's natural history. The most frequent mode of presentation for LV pseudoaneurysm is heart failure with chest pain. However, the variable presentation of this condition requires a high index of suspicion for diagnosis. We report the case of a 75-year-old woman who had suffered an acute myocardial infarction 23 years previously, which resulted in a calcified LV apical aneurysm. Three weeks prior to being referred to our hospital, she was noted by her general practitioner to have a left-sided breast mass although mammography was negative. One week later, she attended the accident and emergency department; she was haemodynamically unstable but was resuscitated successfully. Contrast enhanced computed tomography showed a large haematoma located in the left chest wall communicating with the left ventricle. She underwent emergency cardiac surgical repair. On arrival at the intensive care unit following surgery, her haemodynamic status was unstable, and she deteriorated rapidly and died. With this report, we aim to raise the level of awareness for an apical LV pulsatile mass that could anatomically expand and present as a breast mass or tumour. An early diagnosis and timely surgical intervention is essential in order to achieve better outcomes and avoid detrimental complications.

Delayed aorto-right atrial fistula following percutaneous closure of atrial septal defect.

We present the case of a 27-year-old man who underwent percutaneous atrial septal defect (ASD) repair using the Amplatzer(®) (St Jude Medical, St Paul, MN, US) septal occluder (ASO). Six weeks later, he presented with heart failure and was found to have an aorto-right atrial fistulation. He required urgent surgical device explantation and repair of the existing ASD using a pericardial patch repair technique. This is the first case to be reported from the UK describing a delayed aorto-right atrial fistula following percutaneous closure using ASO.

Autologous osteochondral graft for traumatic defects of finger joints.

Finger joint defects in 16 adults were treated with an autologous osteochondral graft from the base of the second metacarpal, the radial styloid, the base of the third metacarpal or the trapezoid and these patients were followed up from between 12 and 62 months. There was no donor site morbidity. One patient had resorption of the graft and developed pain. The joint was subsequently fused. The mean range of movement was 55.8% of the opposite normal joint. At follow up, 15 patients had no discomfort or mild discomfort. Three had mild narrowing of the joint space and two had slight joint subluxation. Only two patients with concomitant severe injury to the same limb had difficulty performing daily activities. Ten were open injuries and these had poorer outcomes. A hemicondylar defect of a finger joint can be treated using an osteochondral graft obtained from the same hand.

Improving the privacy of optical steganography with temporal phase masks.

Temporal phase modulation of spread stealth signals is proposed and demonstrated to improve optical steganography transmission privacy. After phase modulation, the temporally spread stealth signal has a more complex spectral-phase-temporal relationship, such that the original temporal profile cannot be restored when only dispersion compensation is applied to the temporally spread stealth signals. Therefore, it increases the difficulty for the eavesdropper to detect and intercept the stealth channel that is hidden under a public transmission, even with a correct dispersion compensation device. The experimental results demonstrate the feasibility of this approach and display insignificant degradation in transmission performance, compared to the conventional stealth transmission without temporal phase modulation. The proposed system can also work without a clock transmission for signal synchronization. Our analysis and simulation results show that it is difficult for the adversary to detect the existence of the stealth transmission, or find the correct phase mask to recover the stealth signals.

Dengue vector surveillance and control in Hong Kong in 2008 and 2009.

Dengue vector surveillance programmes were implemented in the community and port areas in Hong Kong Special Administrative Region. Aedes albopictus was the only Aedes vector detected and its distribution was extensive in various areas during the summer months. Aedes aegypti was, however, not detected in any area under surveillance. For community surveillance, the monthly ovitrap indices (MOI) of 2008 and 2009 followed a similar trend as in previous years but were generally lower. The highest ovitrap index recorded in 2008 and 2009 was 37.5% and 48.3% respectively, which were much lower than the highest recorded of 70.9% in 2007. Only two surveyed areas in 2009 had ovitrap indices greater than 20.0% for more than two consecutive months, which was more often seen in 2007. Improvement in the dengue vector situation in the past two years could be attributed to the swift response of the agencies concerned upon getting information on surveillance results via the geographic information system. The public was also informed of the results regularly through the Internet and press releases to create awareness to prevent and control the dengue vector. Health education programmes targeted at different organizations/parties were arranged to promote knowledge about dengue vector prevention and control.

A compact nonlinear fiber-based optical autocorrelation peak discriminator.

We experimentally demonstrate a nonlinear fiber-based optical autocorrelation peak discriminator. The approach exploits four-wave mixing in a 37-cm highly-nonlinear bismuth-oxide fiber that provides a passive and compact means for rejecting cross-correlation peaks. The autocorrelation peak discriminator plays an important role in improving the detection of optical CDMA signals. Eye diagrams and bit-error rates are measured at different power ratios. Significant receiver sensitivity improvements are obtained and error-floors are removed. The experimental results show that the autocorrelation peak discriminator works well even when the amplitudes of individual cross-correlation peaks are higher than that of the autocorrelation peak.

10 GHz pulses generated across a ~100 nm tuning range using a gain-shifted mode-locked SOA ring laser.

Widely-tunable picosecond pulses have been generated from a harmonically mode-locked semiconductor optical amplifier (SOA) ring laser with a center wavelength spanning from 1491 to 1588 nm. An intra-cavity birefringence loop mirror filter is used to define a 1.6 nm comb that governs the wavelength spacing of the tunable output pulses. The filter also serves to control the spectral gain profile of the laser cavity and thus extends the tuning range. By exploiting the spectral shift of the SOA gain with different amount of optical feedback, the output can be obtained over a wid wavelength range. Applying mode-locking together with the dispersion tuning approach, 10 GHz picosecond pulses have been successfully generated over a tuning range of 97 nm.

[A possible molecular mechanism of the narcotic action of noble gases].

A molecular mechanism of the narcotic action of noble gases is suggested, which is based on the fact that noble gas atoms change the orientation of water molecules absorbed on the surface of axon membrane. The resulting change in the transmembrane potential deteriorates the propagation of nerve pulse.

Repetition rate multiplication of multi-wavelength pulses by spectral elimination with a birefringence loop mirror filter.

We demonstrate simultaneous repetition rate multiplication of laser pulses at multiple wavelengths using the spectral elimination approach. The phase coherence between the pulses is preserved while the aggregate bandwidth can be significantly enhanced. The repetition rates of pulses from both a mode-locked fiber ring laser and a pair of gain-switched DFB laser diodes have been multiplied to over 18 GHz per wavelength using the same setup. The key element is an all-fiber, polarization independent birefringence loop mirror comb filter. The broad transmission peaks of the filter also allow a large tolerance in the drift of the input wavelengths and repetition rates. A detuning range of 1.2 GHz is observed, corresponding to 13% of the input frequency.

Optically controlled Sagnac loop comb filter.

We propose a new type of dynamically tunable birefringence comb filter based on a semiconductor optical amplifier Sagnac loop interferometer. By optically modulating the birefringence of the amplifier, we demonstrate a tuning of the output wavelengths. The shift of wavelength increases monotonically with the power of the control light until saturation occurs. The tuning relation is independent of the comb spacing governed by the length and birefringence of the polarization maintaining fiber inside the loop. A tuning range up to 59% of the comb spacing has been achieved at 18.5 dBm input power.

Needlescopic cholecystectomy: prospective study of 150 patients.

OBJECTIVE: To evaluate the feasibility and safety of cholecystectomy using miniaturised instruments of 3 mm or less in diameter. DESIGN: Prospective study on patients with gallstones, with or without related complications. SETTING: Private hospital, Hong Kong. PATIENTS: From September 1997 to September 2002, 150 of the 180 consecutive patients managed were included in the present study. MAIN OUTCOME MEASURES: All patients were operated on with a standard four-port technique. Mini-laparoscopes of different sizes were used throughout the study period, which included 2-mm (n=33) fibre-optic laparoscope, and 2.5-mm (n=61) and 3-mm (n=56) laparoscopes of Hopkins rod lens system. The cystic duct and artery were secured either by extracorporeal ties or 10-mm clips passed through the umbilicus. The time taken from dissection to division of the cystic duct and artery, and to complete the operation were documented. RESULTS: The operation was successfully completed with needlescopic instruments in 127 (85%) patients, even though patients with acute cholecystitis and history of common bile duct stones were included. Use of larger-diameter mini-laparoscopes decreased the time needed to divide the cystic duct and artery, to detach the gall bladder from the liver, and to complete the operation. There were no deaths. One minor bile duct injury developed secondary to extensive cauterisation of the gall bladder fossa. CONCLUSION: Needlescopic cholecystectomy with minor technical modification can be completed within a duration comparable to standard laparoscopy at no increased risk for the great majority of patients with gallstones.