Characteristics, symptom management and outcomes in Covid-19 patients referred to palliative care in a tertiary hospital: A retrospective observational study.

INTRODUCTION: Coronavirus disease 2019 (COVID-19) variants pose unique challenges with inevitable premature death when cases of severe disease exponentially rise in a healthcare system. It is imperative that palliative care is provided with a proactive approach to symptom recognition, assessment, management and treatment escalation to ensure comfort throughout the course of this illness. OBJECTIVES: To evaluate the characteristics, symptom burden, palliative care management and outcomes of COVID-19 patients referred to a palliative care unit (PCU) in a single tertiary hospital. Clinical outcomes specifically observed the management of agitation in these patients based on their Richmond Agitation and Sedation Scale (RASS) scores. METHODS: A retrospective observational study was conducted in a tertiary hospital by reviewing electronic medical records and extracting data from 1st June 2021to 31st July 2021 of all COVID-19 patients referred to the PCU. RESULTS: A cohort of 154 (75 males, 79 females) COVID-19 patients was referred to the PCU with a mean age of 67 (20- 95) years. The median number of days of COVID-19 illness before referral was 7(4-11), with 79.3% of patients being in categories 4 and 5. The median duration of the PCU involvement was 4(1-24) days; 74% of families were engaged in virtual platform communication. The most prevalent symptoms were dyspnoea (73.4%) and agitation (41.6%). Common medications used were opioids, antipsychotics and benzodiazepines. Among agitated patients, none had RASS scores above +2 in the last encounter. Palliative care doctors in the team reported complete effectiveness in patient's symptom control in 74% of patients. CONCLUSIONS: A hallmark of severe COVID-19 is rapid deterioration, which calls for proactive assessment and urgent palliation. Breathlessness and agitation are priority symptoms to address. Among agitated patients, benzodiazepines and antipsychotics are highly effective in addressing agitation and reducing RASS scores. Communication with families using virtual platforms is effective in providing a supportive presence and closure when face-to-face communication is not possible.

Utility of SARS-CoV-2 rapid antigen testing for patient triage in the emergency department: A clinical implementation study in Melbourne, Australia.

Background: Early, rapid detection of SARS-CoV-2 is essential in healthcare settings in order to implement appropriate infection control precautions and rapidly assign patients to care pathways. Rapid testing methods, such as SARS-CoV-2 rapid antigen testing (RAT) may improve patient care, despite a lower sensitivity than real-time PCR (RT-PCR) testing. Methods: Patients presenting to an Emergency Department (ED) in Melbourne, Australia, were risk-stratified for their likelihood of active COVID-19 infection, and a non-randomised cohort of patients were tested by both Abbott Panbio™ COVID-19 Ag test (RAT) and SARS-CoV-2 RT-PCR. Patients with a positive RAT in the 'At or High Risk' COVID-19 group were moved immediately to a COVID-19 ward rather than waiting for a RT-PCR result. Clinical and laboratory data were assessed to determine test performance characteristics; and length of stay in the ED was compared for the different patient cohorts. Findings: Analysis of 1762 paired RAT/RT-PCR samples demonstrated an overall sensitivity of 75.5% (206/273; 95% CI: 69·9-80·4) for the Abbott Panbio™ COVID-12 Ag test, with specificity of 100% (1489/1489; 95% CI: 99·8-100). Sensitivity improved with increasing risk for COVID-19 infection, from 72·4% (95% CI: 52·8-87·3) in the 'No Risk' cohort to 100% (95% CI: 29·2-100) in the 'High Risk' group. Time in the ED for the 'At/High Risk' group decreased from 421 minutes (IQR: 281, 525) for those with a positive RAT result to 274 minutes (IQR:140, 425) for those with a negative RAT result, p = 0.02. Interpretation: The positive predictive value of a positive RAT in this setting was high, allowing more rapid instigation of COVID-19 care pathways and an improvement in patient flow within the ED. Funding: Royal Melbourne Hospital, Melbourne, Australia.

A collaborative emergency decision making approach based on BWM and TODIM under interval 2-tuple linguistic environment.

Emergencies require various emergency departments to collaborate to achieve timely and effective emergency responses. Thus, the overall performance of emergency response is influenced not only by the efficiency of each department alternative but also by the coordination effect among different department alternatives. This paper proposes a collaborative emergency decision making (CEDM) approach considering the synergy among different department alternatives based on the best-worst method (BWM) and TODIM (an acronym in Portuguese of interactive and multiple attribute decision making) method within an interval 2-tuple linguistic environment. First, the evaluation information provided by decision makers (DMs) is represented by interval 2-tuple linguistic variables to reflect and model the underlying diversity and uncertainty. On the basis of the DMs' evaluations, the individual and collaborative performance evaluations of multi-alternative combinations composed of different department alternatives are constructed. Then, the BWM is extended into interval 2-tuple linguistic environment to obtain the weights of evaluation criteria, where the group decision making is taken into account in an interval fuzzy mathematical programming model. Furthermore, to derive more practical and accurate decision results, an interval 2-tuple linguistic TODIM (ITL-TODIM) method is proposed by considering the DMs' psychological behaviours. In the developed ITL-TODIM method, both the gain and loss degrees of one alternative relative to another are simultaneously computed. Finally, a numerical example is presented to illustrate the applicability of the proposed method. Sensitivity and comparative analyses are also provided to demonstrate the effectiveness and advantages of the proposed approach.

Routine antiseptic baths and MRSA decolonization: diverse approaches across Singapore's acute-care hospitals.

To determine the variation in practices on meticillin-resistant Staphylococcus aureus (MRSA) surveillance and management of MRSA-colonized patients amongst 17 acute healthcare facilities in Singapore, the Ministry of Health convened a sharing session with Infection Prevention and Control Leads. All hospitals practised close to universal MRSA entry swabbing in keeping with national policy. There were, however, major variations in the response to both positive and negative surveillance swabs across facilities including the role of routine antiseptic bathing and MRSA decolonization. Most undertaking decolonization considered its role to be in 'bioburden reduction' rather than longer-term clearance.

Atomistic insights into structure evolution and mechanical property of calcium silicate hydrates influenced by nuclear waste caesium.

The fundamental mechanisms underlying the influence of nuclear wastes on concrete properties remain poorly understood, especially at the molecular level. Herein, caesium ions (Cs+) are introduced into calcium silicate hydrates (CSH) to investigate its effect using molecular dynamics simulation. Structurally, a swelling phenomenon is observed, attributed to the CSH interlayer expansion as Cs+ occupies larger space than Ca2+. The diffusion of interlayer water, Ca2+ and Cs+, following an order of water > Cs+ > Ca2+, is accelerated with increasing Cs+ content, owing to three mechanisms: expanded interlayer space, weakened interfacial interaction, and loss of chemical bond stability. Mechanically, the Young's modulus and strength of CSH are degraded by Cs+ due to two mechanisms: (1) the load transfer ability of interlayer water and Ca2+ is weakened; (2) the load transfer provided by Cs+ is very weak. Additionally, a "hydrolytic weakening" mechanism is proposed to explain the mechanical degradation with increasing water content. This study also provides guidance for studying the influence of other wastes (like heavy metal ions) in concrete.

Malignant phyllodes tumors of the breast: A single institution experience.

BACKGROUND: Malignant phyllodes tumors of the breast are uncommon fibroepithelial breast tumors with diverse biological behavior. Our study aim is to share our experience in treating patients with malignant phyllodes presenting to our center. PATIENTS AND METHODS: A total of 11 cases of malignant phyllodes were retrospectively reviewed between Nov 2014 and Oct 2017. RESULTS: The median age was 45 years old (31- 61 years). The median pathological tumor size was 10.5cm (2-28cm). 6 patients (55%) were premenopausal. 7 patients (64%) were treated eventually with mastectomy and 4 (36%) were treated with breast conserving surgery. 4 (36%) patients had Axillary Clearance done while axillary sampling was done in 2 patient. The remainder 5 (45%) required axillary clearance at a later op. 6 (55%) patients received postoperative radiotherapy. After a median follow up period of 11 months (range 4-33 months), 8 developed local recurrence. The overall 2 year survival rate was 18%. CONCLUSION: Malignant Phyllodes tumors are rare tumors that occur in fairly young women, when compared with the adenocarcinoma of the breast. They tend to grow to reach large with absence of nodal metastasis. Ultimately surgery is the mainstay of management but with postoperative radiotherapy it can decrease the local recurrence rates in certain presentations however recurrence rate is high and overall survival rates are poor.

Targeting antimicrobial stewardship in hospitalised patients with community-acquired pneumonia within 24 h of admission.

BACKGROUND: Over-prescribing in patients with respiratory tract infections is common in Australian hospitals. Senior registrar stewardship input within 24 h of admission in hospitalised patients was assessed to determine if this would improve appropriateness. METHODS: Interventional, non-randomised, case-controlled study over six-month period. Patients diagnosed with pneumonia admitted under General Medicine were discussed at morning handover and assessed by a senior registrar within the first 24 h of admission with real-time stewardship feedback provided. Controls did not receive stewardship advice. Appropriateness of antibiotic use was assessed using Therapeutic Guidelines. RESULTS: In total, 48 patients had an intervention with 49 controls. Ceftriaxone-based regimens were the most commonly prescribed (control 63%; pre-intervention 70%; post-intervention 51%). The senior registrar recommended changes in 26 patients (55%) with 71% uptake of recommendations. The most common recommendation was de-escalation from ceftriaxone-regimen in patients with CORB scores of 0 and 1 (79%; n = 16/20). Post-intervention antibiotic prescribing improved from <5% to 50% in patients with CORB scores of 0 and 1 (p-value <0.05). CONCLUSION: Our results demonstrate that involvement of a senior registrar embedded in the treating team is effective in providing timely advice to influence common hospital over-prescribing in patients with pneumonia. This enhances other antimicrobial stewardship activities such as electronic approval systems and dedicated post-prescribing rounds by Antimicrobial Stewardship team.

Experimental study on a comparison of typical premixed combustible gas-air flame propagation in a horizontal rectangular closed duct.

Research surrounding premixed flame propagation in ducts has a history of more than one hundred years. Most previous studies focus on the tulip flame formation and flame acceleration in pure gas fuel-air flame. However, the premixed natural gas-air flame may show different behaviors and pressure dynamics due to its unique composition. Natural gas, methane and acetylene are chosen here to conduct a comparison study on different flame behaviors and pressure dynamics, and to explore the influence of different compositions on premixed flame dynamics. The characteristics of flame front and pressure dynamics are recorded using high-speed schlieren photography and a pressure transducer, respectively. The results indicate that the compositions of the gas mixture greatly influence flame behaviors and pressure. Acetylene has the fastest flame tip speed and the highest pressure, while natural gas has a faster flame tip speed and higher pressure than methane. The Bychkov theory for predicting the flame skirt motion is verified, and the results indicate that the experimental data coincide well with theory in the case of equivalence ratios close to 1.00. Moreover, the Bychkov theory is able to predict flame skirt motion for acetylene, even outside of the best suitable expansion ratio range of 6

Popliteal artery pseudoaneurysm successfully treated with amplatzer vascular plug.

Popliteal artery pseudoaneurysm is uncommon. They usually result from penetrating or blunt trauma, arterial reconstructive surgery, invasive diagnostic or surgical orthopedic procedures. They can cause arterial thrombosis and limb ischeamia. We report a 53 year old Chinese gentleman with popliteal artery pseudoaneurysm who presented with right lower limb numbness and paralysis in toes extension. He gave a history of acupuncture treatment around the popliteal fossa of the affected limb. Clinical examination revealed a pulsatile mass in the popliteal fossa. Computed tomography angiography showed a large, 5 cm, pseudoaneurysm arising from the popliteal artery. A diagnostic angiogram was performed and revealed that there is no run off from the popliteal artery and the tibial vessels were reconstructed from collaterals. Endovascular intervention was carried out with an Amplatzer Vascular Plug to embolise the pseudoaneurysm. The pseudoaneurysm was successfully excluded and post-op follow up revealed no more pulsatile mass and improving lower limb function. To the best of our knowledge this is first reported case of pseudoaneurysm of the popliteal artery secondary to acupuncture in Malaysia.

Structure stability and high-temperature distortion resistance of trilayer complexes formed from graphenes and boron nitride nanosheets.

The molecular dynamics was employed to study the structure stability and high-temperature distortion resistance of a trilayer complex formed by a monolayer graphene sandwiched in bilayer boron nitride nanosheets (BN-G-BN) and graphenes (G-G-G). The investigation shows that the optimal interlayer distances are about 0.347 nm for BN-G-BN and 0.341 nm for G-G-G. Analysis and comparison of the binding energy, van der Waals interactions between layers and radial distribution function (RDF) revealed that the BN-G-BN achieves a more stable combined structure than G-G-G. The interlayer graphene in the trilayer complex nanosheets, especially the graphene in BN-G-BN, is more integrated than monolayer graphenes in a crystal structure. The structures at high temperature of 1500 K show that the BN-G-BN exhibits less distortion than G-G-G; especially, fixing the atomic positions on up-down layers can obviously further reduce structural deformation of interlayer graphene. The result further indicates that the high-temperature distortion resistance of interlayer graphene in the trilayer complex is related to both material type and conditions of constraints at the up-down layers.

Ultra-sensitive analysis of a cantilevered single-walled carbon nanocone-based mass detector.

The ultra-sensitivity of mass detectors using individual cantilevered single-walled carbon nanocone (SWCNC) resonators is first investigated. A higher-order gradient theory, derived at the atomic level, is applied for modeling SWCNC resonators. Numerical simulations using a mesh-free computational framework based on moving Kriging interpolation are conducted to investigate the mass sensitivity of cantilevered SWCNC resonators with extra mass loading as well as with equivalent single-walled carbon nanotube (SWCNT) resonators. Comparison of the magnitude of resonant frequency shifts, the key criterion for mass sensitivity, of these two kinds of resonators demonstrates a far higher mass sensitivity for SWCNC resonators than for SWCNT resonators, thus suggesting a new method for ultra-sensitive mass detection via SWCNC resonators. The dependence of the mass sensitivity of SWCNC resonators on height and top radii has been examined. A reduction in the height of SWCNC resonators gives rise to a considerable increase in mass sensitivity. The mass sensitivity of a 6 nm high SWCNC resonator can even reach a level of 10(-22) g. It is noteworthy that the top radii of SWCNC resonators have a slight effect on frequency shifts. Another interesting observed phenomenon is that a deviation in the height of 19.2° SWCNC resonators leads to little loss in precision of mass detection when the attached mass is smaller than 10(-20) g. This superior characteristic indicates that SWCNC-based mass detectors have great potential in practical applications.

Influence of hydroxyl groups on the adsorption of HCHO on TiO2-B(100) surface by first-principles study.

The adsorption of formaldehyde (HCHO) on both clean and hydroxylated TiO(2)-B(100) surfaces with terminal and bridging hydroxyl groups is systematically investigated by using first principles density functional theory calculations. The discussion is mainly focused on the two different chemical adsorption configurations of HCHO in periodicity (2 × 2), in which the C atom of HCHO is bonded with two coordinated O atoms on a step (Structure I) or on a terrace (Structure II). The study indicates that bridging hydroxyl groups on most of the adsorption sites near to HCHO will weaken the adsorption of HCHO, while terminal hydroxyl groups on most of adsorption sites will facilitate it. The investigation of the effects of hydroxyl groups and H(2)O molecule on HCHO in different periodicities shows that the terminal hydroxyl groups or H(2)O molecules have significantly facilitated the adsorption of H(2)O at larger periodicities, while bridging hydroxyl groups do not have this trend. The analysis of the adsorption mechanisms of HCHO molecules on both clean and hydroxylated surfaces indicate that the terminal hydroxyl groups can extract electrons from the surface and facilitate adsorption of HCHO due to the adsorption energy being higher than that on the clean surface, while the bridging hydroxyl groups donate electrons to the surface and weaken the adsorption. In all chemical adsorption configurations, HCHO acts as an electron acceptor. Interestingly, though the adsorptions are weaker, HCHO in Structure II gains more electrons on both the clean and hydroxylated surfaces than in Structure I. This unique mechanism provides a novel angle to understand the interaction of HCHO with the hydroxylated TiO(2) surface.

Position effects of single vacancy on transport properties of single layer armchair h-BNC heterostructure.

Based on certain single layer armchair h-BNC heterostructures, six molecular devices with different positions of single vacancy atoms are investigated to explain the modulating process of negative differential resistance (NDR) behaviors and rectifying performance. The results show that NDR behaviors can be observed clearly with vacancy atoms near the interface of graphene nano-ribbon and BN nano-ribbon, and rectifying performance can be enhanced obviously when there are vacancy atoms in the moiety of the BN nano-ribbon. The first-principles analysis of the microscopic nature reveals that strength of electronic transmission, evolutions of molecular orbitals and distributions of molecular states are the intrinsic responses to these transport properties.

High-temperature thermal stability and in-plane compressive properties of a graphene and a boron-nitride nanosheet.

The structural performance of graphene and boron-nitride nanosheet (BNNS) with zigzag and armchair types, when subjected to high temperatures, is investigated through molecular dynamics simulations. It is found that the degree of structure distortion is related to chirality; materials at high temperature of 3500 K, the zigzag nanosheet always exhibits less distortion than the armchair for the same material, and the BNNS exhibits less distortion than graphene for the same chirality. Graphene and BNNS with different in-plane compressive strains are optimized by using the Universal Force Field (UFF) method. It is found that there are two entirely different buckling modes, i.e., the lateral buckling of graphene begins to occur at the middle part, whereas buckling of BNNS begins to occur at near both ends and shows lateral deformation in two opposite directions. The coefficient of elasticity of graphene is slightly smaller than that of BNNS for the same chirality, the coefficient of elasticity of zigzag is slightly bigger than that of armchair for the same material, buckling strain of zigzag nanosheet is larger than that of armchair for the same material, and buckling strains of graphene are always larger than those of BNNS. These phenomena are also analyzed on the basis of radial distribution function (RDF) and system energy. The results indicate that there are thermal expansion anisotropy and planar stress anisotropy in a graphene and a BNNS. Among these materials, zigzag graphene has the highest resistance to compressive buckling but zigzag BNNS can have the highest resistance to distortion at high-temperature distortion and have high compression elasticity.

Drug-induced permeabilization of parasite's digestive vacuole is a key trigger of programmed cell death in Plasmodium falciparum.

Having previously characterized chloroquine (CQ)-induced programmed cell death (PCD) hallmarks in the malaria parasite Plasmodium falciparum and delineating a pathway linking these features, the roles of non-classical mediators were investigated in this paper. It was shown that the later stages of this pathway are Ca(2+)-dependent and transcriptionally regulated. Moreover, it was demonstrated for the first time that micromolar concentrations of CQ partially permeabilized the parasite's digestive vacuole (DV) membrane and that this important upstream event appears to precede mitochondrial dysfunction. This permeabilization of the DV occurred without rupture of the DV membrane and was reminiscent of lysosome-mediated cell death in mammalian cells. As such micromolar concentrations of CQ are found in the patient's plasma after initial CQ loading, this alludes to a clinically relevant antimalarial mechanism of the drug which has yet to be recognized. Furthermore, other 'non-antimalarial' lysosomotropic compounds were also shown to cause DV permeabilization, triggering PCD in both CQ-sensitive and -resistant parasites. These findings present new avenues for antimalarial developments, which induce DV destabilization to kill parasites.

High-temperature thermal stability and axial compressive properties of a coaxial carbon nanotube inside a boron nitride nanotube.

The structural performance of double-walled C(5, 5)@BN(10, 10) and C(5, 5)@C(10, 10) nanotubes subject to high temperatures is investigated through molecular dynamics simulations. It is found that the inner tube C(5, 5) in the C(5, 5)@BN(10, 10) exhibits less distortion than that in the C(5, 5)@C(10, 10) at annealing temperatures of 3500 and 4000 K. The C(5, 5)@BN(10, 10) and C(5, 5)@C(10, 10) models with different axial compressive strains are optimized using the universal force field (UFF) method. It is found that the critical buckling strains of the inner tubes in the C(5, 5)@BN(10, 10) and C(5, 5)@C(10, 10) are 12.74% and 9.1%, respectively. The critical buckling strain of the former is larger than that of the latter; although the former exhibits greater deformation and energy loss after buckling than does the latter. These phenomena are also analyzed on the basis of the radial distribution function (RDF) and system energy. The results of this study indicate that the outer tube boron nitride nanotube (BNNT) has a better protective effect on the inner tube than does the outer tube carbon nanotube (CNT) under both high-temperature and lower compressive strain conditions. In these cases, the thermal stability and compressive resistance properties of the C(5, 5)@BN(10, 10) are superior to those of the C(5, 5)@C(10, 10).

Lignin biodegradation and ligninolytic enzyme studies during biopulping of Acacia mangium wood chips by tropical white rot fungi.

White rot fungi are good lignin degraders and have the potential to be used in industry. In the present work, Phellinus sp., Daedalea sp., Trametes versicolor and Pycnoporus coccineus were selected due to their relatively high ligninolytic enzyme activity, and grown on Acacia mangium wood chips under solid state fermentation. Results obtained showed that manganese peroxidase produced is far more compared to lignin peroxidase, suggesting that MnP might be the predominating enzymes causing lignin degradation in Acacia mangium wood chips. Cellulase enzyme assays showed that no significant cellulase activity was detected in the enzyme preparation of T. versicolor and Phellinus sp. This low cellulolytic activity further suggests that these two white rot strains are of more interest in lignin degradation. The results on lignin losses showed 20-30% of lignin breakdown at 60 days of biodegradation. The highest lignin loss was found in Acacia mangium biotreated with T. versicolor after 60 days and recorded 26.9%, corresponding to the percentage of their wood weight loss recorded followed by P. coccineus. In general, lignin degradation was only significant from 20 days onwards. The overall percentage of lignin weight loss was within the range of 1.02-26.90% over the biodegradation periods. Microscopic observations conducted using scanning electron microscope showed that T. versicolor, P. coccineus, Daedalea sp. and Phellinus sp. had caused lignin degradation in Acacia mangium wood chips.

Nonlocal continuum model and molecular dynamics for free vibration of single-walled carbon nanotubes.

Free transverse, longitudinal and torsional vibrations of single-walled carbon nanotubes (SWCNTs) are investigated through nonlocal beam model, nonlocal rod model and verified by molecular dynamics (MD) simulations. The nonlocal Timoshenko beam model offers a better prediction of the fundamental frequencies of shorter SWCNTs, such as a (5, 5) SWCNT shorter than 3.5 nm, than local beam models. The nonlocal rod model is employed to study the longitudinal and torsional vibrations of SWCNT and found to enable a good prediction of the MD results for shorter SWCNTs. Nonlocal and local continuum models provide a good agreement with MD results for relatively longer SWCNTs, such as (5, 5) SWCNTs longer than 3.5 nm. The scale parameter in nonlocal beam and rod models is estimated by calibrations from MD results.