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1.
Hong Kong Med J ; 30(2): 120-129, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38590159

ABSTRACT

INTRODUCTION: The Newborn Screening Programme for Inborn Errors of Metabolism (NBSIEM) enables early intervention and prevents premature mortality. Residual dried bloodspots (rDBS) from the heel prick test are a valuable resource for research. However, there is minimal data regarding how stakeholders in Hong Kong view the retention and secondary use of rDBS. This study aimed to explore views of the NBSIEM and the factors associated with retention and secondary use of rDBS among healthcare professionals in Hong Kong. METHODS: Between August 2021 and January 2022, semi-structured interviews were conducted with 30 healthcare professionals in obstetrics, paediatrics, and chemical pathology. Key themes were identified through thematic analysis, including views towards the current NBSIEM and the retention and secondary use of rDBS. RESULTS: After implementation of the NBSIEM, participants observed fewer patients with acute decompensation due to undiagnosed inborn errors of metabolism. The most frequently cited clinical utilities were early detection and improved health outcomes. Barriers to rDBS storage and its secondary use included uncertain value and benefits, trust concerns, and consent issues. CONCLUSION: This study highlighted healthcare professionals' concerns about the NBSIEM and uncertainties regarding the handling or utilisation of rDBS. Policymakers should consider these concerns when establishing new guidelines.


Subject(s)
Health Personnel , Interviews as Topic , Metabolism, Inborn Errors , Neonatal Screening , Qualitative Research , Humans , Neonatal Screening/ethics , Hong Kong , Infant, Newborn , Metabolism, Inborn Errors/diagnosis , Female , Health Personnel/psychology , Male , Attitude of Health Personnel , Adult
2.
Zhonghua Yi Xue Za Zhi ; 104(13): 1043-1049, 2024 Apr 02.
Article in Chinese | MEDLINE | ID: mdl-38561299

ABSTRACT

Objective: To evaluate the clinical efficacy of posterior lumbar interbody fusion combined with Ponte osteotomy in the treatment of patients with degenerative scoliosis. Methods: The medical records and imaging data of degenerative scoliosis in department of orthopedics, Peking Union Medical College Hospital from 2013 to 2022 were retrospectively collected, and the shortest follow-up time was 1 year. A total of 38 patients were included, including 13 males and 25 females, aged 50-87(65.6±10.9) years old.The follow-up was12-119(43±20) months. Standing position full spine anteroposterior lateral X-ray examinations were performed on all patients preoperatively, postoperatively, and at latest follow-up. The length of hospital stay, complications, operation time, blood loss, instrumented segment, fusion segmen were recorded. The clinical scores and coronasagittal imaging indicators at three time points were compared. Results: The operation time was (274.5±70.5)min, and intraoperative blood loss was (619.2±93.5)ml. The coronal vertical axis was improved from (2.9±1.8)cm preoperatively to (1.2±1.0)cm postoperatively. The preoperative coronal Cobb angle was 16.6°±9.9° and the immediate postoperative correction was 6.4°±4.0°(t=-6.83, P<0.001). The difference was statistically significant (t=-6.12, P<0.001). The coronal Cobb Angle at the last follow-up was 5.7°±3.7°, and there was no significant orthopaedic loss at the last follow-up (t=-6.12, P<0.001).The sagittal vertical axis decreased from (5.6±3.9)cm preoperatively to (3.2±2.5) cm immediately after operation (t=-6.83,P<0.001), and was well maintained at the last follow-up[(2.7±1.8) cm,t=-7.77,P<0.001]. Lumbar lordosis increased from 21.8°±10.2° preoperatively to 35.8°±8.3° postoperatively(t=12.01, P<0.001)and 40.1°±8.6° at last follow-up(t=-10.21, P<0.001). Oswestry disability score (ODI score), visual analogue score (VAS) low back pain score and VAS leg pain score were also lower after surgery than before surgery (all P<0.05). Conclusion: Posterior lumbar interbody fusion combined with Ponte osteotomy can significantly improve the coronal and sagittal plane deformity and postoperative functional score in adult patients with degenerative scoliosis.


Subject(s)
Scoliosis , Spinal Fusion , Adult , Male , Female , Humans , Middle Aged , Aged , Scoliosis/surgery , Retrospective Studies , Spinal Fusion/methods , Lumbar Vertebrae/surgery , Treatment Outcome , Osteotomy
3.
Phys Rev Lett ; 132(3): 035101, 2024 Jan 19.
Article in English | MEDLINE | ID: mdl-38307081

ABSTRACT

Magnetic reconnection is a ubiquitous and fundamental process in plasmas by which magnetic fields change their topology and release magnetic energy. Despite decades of research, the physics governing the reconnection process in many parameter regimes remains controversial. Contemporary reconnection theories predict that long, narrow current sheets are susceptible to the tearing instability and split into isolated magnetic islands (or plasmoids), resulting in an enhanced reconnection rate. While several experimental observations of plasmoids in the regime of low-to-intermediate ß (where ß is the ratio of plasma thermal pressure to magnetic pressure) have been made, there is a relative lack of experimental evidence for plasmoids in the high-ß reconnection environments which are typical in many space and astrophysical contexts. Here, we report strong experimental evidence for plasmoid formation in laser-driven high-ß reconnection experiments.

4.
Phys Rev E ; 108(3-2): 035209, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37849111

ABSTRACT

Laser-direct-drive fusion target designs with solid deuterium-tritium (DT) fuel, a high-Z gradient-density pusher shell (GDPS), and a Au-coated foam layer have been investigated through both 1D and 2D radiation-hydrodynamic simulations. Compared with conventional low-Z ablators and DT-push-on-DT targets, these GDPS targets possess certain advantages of being instability-resistant implosions that can be high adiabat (α≥8) and low hot-spot and pusher-shell convergence (CR_{hs}≈22 and CR_{PS}≈17), and have a low implosion velocity (v_{imp}<3×10^{7}cm/s). Using symmetric drive with laser energies of 1.9 to 2.5MJ, 1D lilac simulations of these GDPS implosions can result in neutron yields corresponding to ≳50-MJ energy, even with reduced laser absorption due to the cross-beam energy transfer (CBET) effect. Two-dimensional draco simulations show that these GDPS targets can still ignite and deliver neutron yields from 4 to ∼10MJ even if CBET is present, while traditional DT-push-on-DT targets normally fail due to the CBET-induced reduction of ablation pressure. If CBET is mitigated, these GDPS targets are expected to produce neutron yields of >20MJ at a driven laser energy of ∼2MJ. The key factors behind the robust ignition and moderate energy gain of such GDPS implosions are as follows: (1) The high initial density of the high-Z pusher shell can be placed at a very high adiabat while the DT fuel is maintained at a relatively low-entropy state; therefore, such implosions can still provide enough compression ρR>1g/cm^{2} for sufficient confinement; (2) the high-Z layer significantly reduces heat-conduction loss from the hot spot since thermal conductivity scales as ∼1/Z; and (3) possible radiation trapping may offer an additional advantage for reducing energy loss from such high-Z targets.

5.
Rev Sci Instrum ; 94(3): 033510, 2023 Mar 01.
Article in English | MEDLINE | ID: mdl-37012781

ABSTRACT

The Particle Time of Flight (PTOF) diagnostic is a chemical vapor deposition diamond detector used for measuring multiple nuclear bang times at the National Ignition Facility. Due to the non-trivial, polycrystalline structure of these detectors, individual characterization and measurement are required to interrogate the sensitivity and behavior of charge carriers. In this paper, a process is developed for determining the x-ray sensitivity of PTOF detectors and relating it to the intrinsic properties of the detector. We demonstrate that the diamond sample measured has a significant non-homogeneity in its properties, with the charge collection well described by a linear model ax + b, where a = 0.63 ± 0.16 V-1 mm-1 and b = 0.00 ± 0.04 V-1. We also use this method to confirm an electron to hole mobility ratio of 1.5 ± 1.0 and an effective bandgap of 1.8 eV rather than the theoretical 5.5 eV, leading to a large sensitivity increase.

9.
Phys Rev E ; 106(5): L053201, 2022 Nov.
Article in English | MEDLINE | ID: mdl-36559377

ABSTRACT

We report on measurements of the ion-electron energy-transfer cross section utilizing low-velocity ion stopping in high-energy-density plasmas at the OMEGA laser facility. These measurements utilize a technique that leverages the close relationship between low-velocity ion stopping and ion-electron equilibration. Shock-driven implosions of capsules filled with D^{3}He gas doped with a trace amount of argon are used to generate densities and temperatures in ranges from 1×10^{23} to 2×10^{24} cm^{-3} and from 1.4 to 2.5 keV, respectively. The energy loss of 1-MeV DD tritons and 3.7-MeV D^{3}He alphas that have velocities lower than the average velocity of the thermal electrons is measured. The energy loss of these ions is used to determine the ion-electron energy-transfer cross section, which is found to be in excellent agreement with quantum-mechanical calculations in the first Born approximation. This result provides an experimental constraint on ion-electron energy transfer in high-energy-density plasmas, which impacts the modeling of alpha heating in inertial confinement fusion implosions, magnetic-field advection in stellar atmospheres, and energy balance in supernova shocks.

10.
Rev Sci Instrum ; 93(11): 113540, 2022 Nov 01.
Article in English | MEDLINE | ID: mdl-36461452

ABSTRACT

A system of x-ray imaging spectrometer (XRIS) has been implemented at the OMEGA Laser Facility and is capable of spatially and spectrally resolving x-ray self-emission from 5 to 40 keV. The system consists of three independent imagers with nearly orthogonal lines of sight for 3D reconstructions of the x-ray emission region. The distinct advantage of the XRIS system is its large dynamic range, which is enabled by the use of tantalum apertures with radii ranging from 50 µm to 1 mm, magnifications of 4 to 35×, and image plates with any filtration level. In addition, XRIS is capable of recording 1-100's images along a single line of sight, facilitating advanced statistical inference on the detailed structure of the x-ray emitting regions. Properties such as P0 and P2 of an implosion are measured to 1% and 10% precision, respectively. Furthermore, Te can be determined with 5% accuracy.

11.
Rev Sci Instrum ; 93(11): 113534, 2022 Nov 01.
Article in English | MEDLINE | ID: mdl-36461490

ABSTRACT

Charged particle spectrometry is a critical diagnostic to study inertial-confinement-fusion plasmas and high energy density plasmas. The OMEGA Laser Facility has two fixed magnetic charged particle spectrometers (CPSs) to measure MeV-ions. In situ calibration of these spectrometers was carried out using 241Am and 226Ra alpha emitters. The alpha emission spectrum from the sources was measured independently using surface-barrier detectors (SBDs). The energy dispersion and broadening of the CPS systems were determined by comparing the CPS measured alpha spectrum to that of the SBD. The calibration method significantly constrains the energy dispersion, which was previously obtained through the measurement of charged particle fusion products. Overall, a small shift of 100 keV was observed between previous and the calibration done in this work.

12.
Hong Kong Med J ; 28(6): 447-456, 2022 12.
Article in English | MEDLINE | ID: mdl-36423912

ABSTRACT

INTRODUCTION: This retrospective study was conducted to identify the characteristics of paediatric high-grade osteosarcoma and define its prognostic factors. METHODS: We identified paediatric patients (aged <19 years at diagnosis) diagnosed with high-grade osteosarcoma from 1 January 2009 to 31 December 2018 in two hospitals in Hong Kong, then retrospectively evaluated their medical records to identify prognostic factors. RESULTS: In total, 52 patients were included in this study (22 girls, 42.3%). Femoral tumour was the most common form of osteosarcoma. Most patients (78.8%) had localised disease at diagnosis. The lung was the most common site of metastasis. Almost half (n=23, 46.9%) of the patients showed a good response to chemotherapy (ie, chemonecrosis >90%). Most patients (n=40, 80%) underwent limb-salvage surgery. The event-free survival and overall survival rates were 55.8% and 71.2%, respectively. Prognostic factors independently associated with poor event-free survival and poor overall survival were the presence of metastasis at diagnosis, poor tumour chemonecrosis, and the need for amputation. CONCLUSION: This multicentre review of paediatric high-grade osteosarcoma showed that the baseline patient demographics, event-free survival, and overall survival in Hong Kong were similar to previous findings in other countries. Patients with metastatic disease at diagnosis and poor chemonecrosis had worse survival outcomes. Molecular analyses of genetic abnormalities may help to identify targeted therapies in future studies.


Subject(s)
Bone Neoplasms , Osteosarcoma , Female , Child , Humans , Retrospective Studies , Bone Neoplasms/pathology , Prognosis , Osteosarcoma/drug therapy , Osteosarcoma/pathology , Survival Rate
14.
Nature ; 609(7928): 685-688, 2022 09.
Article in English | MEDLINE | ID: mdl-36131036

ABSTRACT

Fast radio bursts (FRBs) are highly dispersed, millisecond-duration radio bursts1-3. Recent observations of a Galactic FRB4-8 suggest that at least some FRBs originate from magnetars, but the origin of cosmological FRBs is still not settled. Here we report the detection of 1,863 bursts in 82 h over 54 days from the repeating source FRB 20201124A (ref. 9). These observations show irregular short-time variation of the Faraday rotation measure (RM), which scrutinizes the density-weighted line-of-sight magnetic field strength, of individual bursts during the first 36 days, followed by a constant RM. We detected circular polarization in more than half of the burst sample, including one burst reaching a high fractional circular polarization of 75%. Oscillations in fractional linear and circular polarizations, as well as polarization angle as a function of wavelength, were detected. All of these features provide evidence for a complicated, dynamically evolving, magnetized immediate environment within about an astronomical unit (AU; Earth-Sun distance) of the source. Our optical observations of its Milky-Way-sized, metal-rich host galaxy10-12 show a barred spiral, with the FRB source residing in a low-stellar-density interarm region at an intermediate galactocentric distance. This environment is inconsistent with a young magnetar engine formed during an extreme explosion of a massive star that resulted in a long gamma-ray burst or superluminous supernova.

15.
Phys Rev E ; 105(6): L063202, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35854613

ABSTRACT

In laser-produced high-energy-density plasmas, large-scale strong magnetic fields are spontaneously generated by the Biermann battery effects when temperature and density gradients are misaligned. Saturation of the magnetic field takes place when convection and dissipation balance field generation. While theoretical and numerical modeling provide useful insight into the saturation mechanisms, experimental demonstration remains elusive. In this letter, we report an experiment on the saturation dynamics and scaling of Biermann battery magnetic field in the regime where plasma convection dominates. With time-gated charged-particle radiography and time-resolved Thomson scattering, the field structure and evolution as well as corresponding plasma conditions are measured. In these conditions, the spatially resolved magnetic fields are reconstructed, leading to a picture of field saturation with a scaling of B∼1/L_{T} for a convectively dominated plasma, a regime where the temperature gradient scale (L_{T}) exceeds the ion skin depth.

16.
Hong Kong Med J ; 28(3): 204-214, 2022 06.
Article in English | MEDLINE | ID: mdl-35697524

ABSTRACT

INTRODUCTION: Compared with young children who have acute lymphoblastic leukaemia (ALL), adolescents with ALL have unfavourable disease profiles and worse survival. However, limited data are available regarding the characteristics and outcomes of adolescents with ALL who underwent treatment in clinical trials. The aim of this study was to investigate the causes of treatment failure in adolescents with ALL. METHODS: We retrospectively analysed the outcomes of 711 children with ALL, aged 1-18 years, who were enrolled in five clinical trials of paediatric ALL treatment between 1993 and 2015. RESULTS: Among the 711 children with ALL, 530 were young children (1-9 years at diagnosis) and 181 were adolescents (including 136 younger adolescents [10-14 years] and 45 older adolescents [15-18 years]). Compared with young children who had ALL, adolescents with ALL were less likely to have favourable genetic features and more likely to demonstrate poor early response to treatment. The 10-year overall survival and event-free survival rates were significantly lower among adolescents than among young children (77.9% vs 87.6%, P=0.0003; 69.7% vs 76.5%, P=0.0117). There were no significant differences in the 10-year cumulative incidence of relapse, but the 10-year cumulative incidence of treatment-related death (TRD) was significantly greater among adolescents (7.2%) than among young children (2.3%; P=0.002). Multivariable analysis showed that both younger and older adolescents (vs young children) had worse survival and greater incidence of TRD. CONCLUSION: Adolescents with ALL had worse survival because they experienced a greater incidence of TRD. There is a need to investigate optimal treatment adjustments and novel targeted agents to achieve better survival rates (without excessive toxicity) among adolescents with ALL.


Subject(s)
Neoplasm Recurrence, Local , Precursor Cell Lymphoblastic Leukemia-Lymphoma , Adolescent , Antineoplastic Combined Chemotherapy Protocols , Child , Child, Preschool , Disease-Free Survival , Humans , Incidence , Neoplasm Recurrence, Local/drug therapy , Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy , Retrospective Studies , Survival Rate
17.
Phys Rev Lett ; 128(19): 195002, 2022 May 13.
Article in English | MEDLINE | ID: mdl-35622051

ABSTRACT

This Letter presents the first observation on how a strong, 500 kG, externally applied B field increases the mode-two asymmetry in shock-heated inertial fusion implosions. Using a direct-drive implosion with polar illumination and imposed field, we observed that magnetization produces a significant increase in the implosion oblateness (a 2.5× larger P2 amplitude in x-ray self-emission images) compared with reference experiments with identical drive but with no field applied. The implosions produce strongly magnetized electrons (ω_{e}τ_{e}≫1) and ions (ω_{i}τ_{i}>1) that, as shown using simulations, restrict the cross field heat flow necessary for lateral distribution of the laser and shock heating from the implosion pole to the waist, causing the enhanced mode-two shape.

18.
Hong Kong Med J ; 28(1): 33-44, 2022 Feb.
Article in English | MEDLINE | ID: mdl-35086965

ABSTRACT

INTRODUCTION: Lifestyle choices may influence health outcomes in cancer survivors. This study of childhood cancer survivors in Hong Kong investigated factors associated with health-protective and health-damaging behaviours; it also examined expectations of a survivorship programme. METHODS: This cross-sectional study recruited survivors of childhood cancer ≥2 years after treatment. Survivors completed a structured questionnaire to report their health practices and the perceived values of survivorship programme components. Multivariable logistic regression analysis was conducted to identify factors associated with health behaviours. RESULTS: Two hundred survivors were recruited (mean age=23.4 ± 8.8 years; mean duration since treatment, 13.4 ± 7.6 years). Comparatively few survivors exercised ≥4 days/week (16.0%), used sun protection (18.0%), and had a balanced diet (38.5%). Furthermore, comparatively few survivors reported that they had not undergone any immunisation (24.5%) or were unsure (18.5%) about their immunisation history. Most adult survivors were never-drinkers (71.0%) and never-smokers (93.0%). Brain tumour survivors were more likely to have unhealthy eating habits, compared with haematological malignancy survivors (odds ratio [OR]=2.45; 95% confidence interval [CI]=1.29-4.68). Lower socioeconomic status was associated with inadequate sun protection (OR=0.20; 95% CI=0.05-0.83), smoking (OR=5.13; 95% CI=1.48-17.75), and exposure to second-hand smoke (OR=3.52; 95% CI=1.42-8.69). Late-effects screening (78.5%) and psychosocial services to address psychological distress (77%) were considered essential components of a survivorship programme. CONCLUSIONS: Despite the low prevalences of health-damaging behaviours, local survivors of childhood cancer are not engaging in health-protective behaviours. A multidisciplinary programme addressing late effects and psychosocial aspects may address the multifaceted needs of this special population.


Subject(s)
Cancer Survivors , Neoplasms , Adolescent , Adult , Cancer Survivors/psychology , Child , Cross-Sectional Studies , Health Behavior , Hong Kong/epidemiology , Humans , Motivation , Neoplasms/psychology , Neoplasms/therapy , Survivors , Survivorship , Young Adult
19.
Zhonghua Liu Xing Bing Xue Za Zhi ; 42(6): 1076-1079, 2021 Jun 10.
Article in Chinese | MEDLINE | ID: mdl-34814510

ABSTRACT

Objective: Diet balance index (DBI_16) was used to evaluate the dietary status of smoking adults in Tianjin, and the relationship between DBI_16 and serum uric acid was analyzed. Methods: A total of 1 478 inhabitants aged 18 and above were enrolled. The dietary status was obtained with a 3-day dietary recall and condiment weighing method. And their fasting venous blood was collected to detect uric acid. Food intake and DBI_16 scores of smokers and non-smokers were described, and the relationship among smoking, diet quality distance (DQD-DBI), and serum uric acid was analyzed. Results: The intake of vegetables, fruits, and milk of smokers in Tianjin was lower than while the salt, oil, cereals, and aquatic products were higher than that of non-smokers. The DBI_16 scores of vegetables and fruits, food types, milk, and beans of smokers were lower than those of non-smokers in Tianjin, and the scores of pure energy foods and condiments were higher than those of the non-smokers. The DQD-DBI, high bound score and low bound score of smokers in Tianjin were 42.0, 14.0, and 29.0 respectively, which were all higher than those of non-smokers. The main problems appeared as moderately inadequate intake (accounting for 67.0%), low, excessive intake (accounting for 70.9%), and moderate imbalance of intake (accounting for 67.2%). The serum uric acid of smokers was higher than in the non-smokers, and there the same result appeared under the conditions of "not suitable" in DQD-DBI. Conclusions: In Tianjin, the dietary imbalance was more evident in smokers than the non-smokers, and the serum uric acid was significantly higher than the non-smokers. Strategies as strengthening the nutrition education and intervention targeted for smokers were in urgent need.


Subject(s)
Diet , Uric Acid , Adult , Diet Surveys , Humans , Smoking , Vegetables
20.
Zhonghua Liu Xing Bing Xue Za Zhi ; 42(7): 1213-1217, 2021 Jul 10.
Article in Chinese | MEDLINE | ID: mdl-34814533

ABSTRACT

Objective: To understand the influence of birth weight on the risk of chronic diseases, such as hypertension and diabetes, and the relationship between birth weight and serum uric acid in adulthood. Methods: According to the Chinese Adult Chronic Disease and Nutrition Surveillance Program, a total of 1 131 residents aged 18 years and above were enrolled from Hexi, Nankai, Hongqiao, Wuqing, Jinnan, Baodi and Jizhou districts of Tianjin. The data of birth weight and blood pressure of the residents were collected, and fasting venous blood samples were collected from them to detect uric acid, blood glucose and blood lipids levels. The distribution of birth weight of the surveyed population was described, and the relationship between birth weight and chronic diseases, such as hypertension and diabetes, and the blood uric acid level in adulthood were analyzed. Results: The average birth weight of the surveyed population in Tianjin was 3.37 kg, which was higher in males than in females. No matter overweight/obesity, hypertension or diabetes, the prevalence rate of normal birth weight was the lowest in adulthood. After univariate logistic regression analysis and adjusting for age, sex, smoking and drinking status, it was found that compared with normal birth weight, low birth weight had a stronger correlation with diabetes (OR=2.91,95%CI:1.46-5.76) and dyslipidemia (OR=1.79,95%CI:1.01-3.19) in adulthood. Macrosomia was strongly associated with overweight/obesity in adulthood (OR=1.47, 95%CI:1.08-2.01). There was no significant difference in serum uric acid level among the residents with different birth weights. Conclusions: The low birth weight of the surveyed population in Tianjin was closely related to the risk of diabetes and dyslipidemia in adulthood, and the macrosomia was closely related to the risk of overweight/obesity in adulthood.


Subject(s)
Fetal Macrosomia , Uric Acid , Adult , Birth Weight , Body Mass Index , Chronic Disease , Female , Humans , Male , Pregnancy , Risk Factors
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