Observation of the effect of gravity on the motion of antimatter.

Einstein's general theory of relativity from 19151 remains the most successful description of gravitation. From the 1919 solar eclipse2 to the observation of gravitational waves3, the theory has passed many crucial experimental tests. However, the evolving concepts of dark matter and dark energy illustrate that there is much to be learned about the gravitating content of the universe. Singularities in the general theory of relativity and the lack of a quantum theory of gravity suggest that our picture is incomplete. It is thus prudent to explore gravity in exotic physical systems. Antimatter was unknown to Einstein in 1915. Dirac's theory4 appeared in 1928; the positron was observed5 in 1932. There has since been much speculation about gravity and antimatter. The theoretical consensus is that any laboratory mass must be attracted6 by the Earth, although some authors have considered the cosmological consequences if antimatter should be repelled by matter7-10. In the general theory of relativity, the weak equivalence principle (WEP) requires that all masses react identically to gravity, independent of their internal structure. Here we show that antihydrogen atoms, released from magnetic confinement in the ALPHA-g apparatus, behave in a way consistent with gravitational attraction to the Earth. Repulsive 'antigravity' is ruled out in this case. This experiment paves the way for precision studies of the magnitude of the gravitational acceleration between anti-atoms and the Earth to test the WEP.

Stability and Cooling of the C_{7}

We have studied the stability of the smallest long-lived all carbon molecular dianion (C_{7}^{2-}) in new time domains and with a single ion at a time using a cryogenic electrostatic ion-beam storage ring. We observe spontaneous electron emission from internally excited dianions on millisecond timescales and monitor the survival of single colder C_{7}^{2-} molecules on much longer timescales. We find that their intrinsic lifetime exceeds several minutes-6 orders of magnitude longer than established from earlier experiments on C_{7}^{2-}. This is consistent with our calculations of vertical electron detachment energies predicting one inherently stable isomer and one isomer which is stable or effectively stable behind a large Coulomb barrier for C_{7}^{2-}→C_{7}^{-}+e^{-} separation.

Partner bereavement when parenting dependent children: What factors influence adjustment?

Little is known about those who are widowed while raising dependent children. This study aimed to explore the factors which influence adjustment to partner death. Seven fathers and five mothers were interviewed, and constructivist grounded theory was used. Three interrelated themes were identified: Interpersonal influences, Intrapersonal influences, and Contextual influences. Dependent children meant sole responsibility and increased demands, yet ultimately provided widowed parents a purpose. Participants highlighted the need for increased awareness of young widowhood at a systemic and cultural level, to improve communication around death and young widowhood. Implications included social, financial and therapeutic interventions.

A comparison of gastric gas volumes measured by computed tomography after high-flow nasal oxygen therapy or conventional facemask ventilation.

High-flow nasal oxygen therapy is increasingly used to improve peri-intubation oxygenation. However, it is unknown whether it may cause or exacerbate insufflation of gas into the stomach. High-flow nasal oxygen therapy is now standard practice in our hospital for adult patients undergoing percutaneous thermal ablation of liver cancer under general anaesthesia with tracheal intubation. We compared gastric gas volumes measured from computed tomography images that had been acquired immediately after intubation in two series of patients: 50 received peri-intubation high-flow nasal oxygen therapy and another 50 received conventional facemask pre-oxygenation and ventilation before intubation and before high-flow nasal oxygen therapy became standard practice in our unit. Median (IQR [range]) gastric gas volume was 24.0 (14.2-59.9 [3-167]) cm3 in the high-flow nasal oxygen therapy group and 23.8 (12.6-38.8 [0-185]) cm3 in the facemask group. There was no difference between the two groups in the volume of gastric gas measured by computed tomography imaging (Mann-Whitney U-test, U = 1136, p = 0.432, n1  = n2  = 50). Our results demonstrate that a small volume of gastric gas is commonly present after induction of anaesthesia, but that the use of peri-intubation high-flow nasal oxygen therapy for pre-oxygenation and during apnoea does not increase this volume compared with conventional facemask pre-oxygenation and ventilation. This is clinically relevant, as high-flow nasal oxygen therapy is increasingly being used in a peri-intubation context and in patients at higher risk of aspiration.

An essential model for leaders to enable integrated working to flourish: a qualitative study examining leaders of Children's Centers.

Today's era of integrated working seeks to bring together different professionals to work in patient-centered teams. As a result leadership perspectives have changed. We now seek leaders who recognize the complexity of moderating across different health, social care and other public and private sector organizations for collective patient/community focussed service. This research focuses on the role of leaders in the UK who were asked to lead a range of practitioners working from Children's Centers. These centers brought together a myriad of practitioners from health, social care, and education to meet the needs of children from wide and diverse backgrounds. We share a qualitative study, exploring the experiences of Children's Center leaders, using critical theory and constructivism. The study explored how leaders enable integrated working to flourish. The research was conducted in two stages: In Stage One, five strategic Children's Center managers were interviewed to illuminate the key ingredients felt to support good leaders. Stage Two brought together 10 Children's Center leaders from across different areas of the UK, to share their experiences using Participatory Action Research. The final synthesis identified four main processes which could help leaders to enable integrated working to flourish. These were: i) Thinking Systematically; ii) Building and re-building relationships; ii) Nourishing self-actualization and; iv) Utilizing alternative approaches to problem solving. Four borderline processes were identified: Interaction, Integrity, Flow and Sensitivity. The final model articulates the skills required to lead integrated services which bring together a wide range of practitioners. The outcomes help leaders to explore new ways of leading and require further testing. The outcomes may apply to other clinical areas of integrated working.

Implementation of child mental health service improvement plans in four low- and middle-income countries: stakeholders' perspectives.

Children in low- and middle-income countries (LMIC) have high levels of unmet mental health needs, especially in disadvantaged communities. To address this gap, we developed a child mental health service improvement programme. This was co-facilitated using interprofessional principles and values in four countries, South Africa, Kenya, Turkey and Brazil. Eighteen stakeholders from different professions were interviewed after six months on their perspectives on enabling factors and challenges they faced in implementing service plans. Participants valued the holistic case management approach and scaled service model that underpinned the service plans. Emerging themes on participants' priorities related to service user participation, integrated care, and different levels of capacity-building. We propose that an integrated care model in LMIC contexts can maximize available resources, engage families and mobilize communities. Implementation requires concurrent actions at micro-, meso- and macro-level.

Reflections on low-dose radiation, the misconceptions, reality and moving forward.

Low dose radiation has been widely accepted by the radiation protection community as presenting a very low risk to human health, if any. Over-conservatism in optimisation principles and regulations have resulted in a disproportionate fear of radiation amongst the general public and government authorities alike, overlooking the great benefits nuclear science and techniques have brought to society as a whole. As such, the World Nuclear Association advocates for a recontextualisation of the radiation hazards with regards to low dose radiation, and a greater awareness as to the absence of any discernible effects associated with it.

Reflection on the proposed changes to dose quantities-an industrial perspective.

In 2021, the ICRP initiated the revision of the general recommendations of the system of radiation protection, and part of it will focus on dose quantities. The recently published ICRP Publication 147 and ICRU Report 95 have described the extent of the proposed modifications and paved the way for the strategy to be adopted. These revisions would seek to simplify, improve the accuracy and extend the field of use of dose quantities. While the Radiological Protection Working Group of the World Nuclear Association recognises the notable improvement in the estimation of the protection quantities and the usefulness of such changes for the medical and research sector, the benefits of the proposed new system seem very limited for the nuclear industry and industries involving naturally occurring radioactive materials. The complexity associated with changing a long-standing and robust system and the risk incurred by the human factor seem unjustified, bearing in mind the likely cost.

Spontaneous Electron Emission from Hot Silver Dimer Anions: Breakdown of the Born-Oppenheimer Approximation.

We report the first experimental evidence of spontaneous electron emission from a homonuclear dimer anion through direct measurements of Ag_{2}^{-}→Ag_{2}+e^{-} decays on milliseconds and seconds timescales. This observation is very surprising as there is no avoided crossing between adiabatic energy curves to mediate such a process. The process is weak, yet dominates the decay signal after 100 ms when ensembles of internally hot Ag_{2}^{-} ions are stored in the cryogenic ion-beam storage ring, DESIREE, for 10 s. The electron emission process is associated with an instantaneous, very large reduction of the vibrational energy of the dimer system. This represents a dramatic deviation from a Born-Oppenheimer description of dimer dynamics.

Burden of respiratory syncytial virus hospitalisation among infants born at 32-35 weeks' gestational age in the Northern Hemisphere: pooled analysis of seven studies.

To provide comprehensive information on the epidemiology and burden of respiratory syncytial virus hospitalisation (RSVH) in preterm infants, a pooled analysis was undertaken of seven multicentre, prospective, observational studies from across the Northern Hemisphere (2000-2014). Data from all 320-356 weeks' gestational age (wGA) infants without comorbidity were analysed. RSVH occurred in 534/14 504 (3.7%) infants; equating to a rate of 5.65 per 100 patient-seasons, with the rate in individual wGA groups dependent upon exposure time (P = 0.032). Most RSVHs (60.1%) occurred in December-January. Median age at RSVH was 88 days (interquartile range (IQR): 54-159). Respiratory support was required by 82.0% of infants: oxygen in 70.4% (median 4 (IQR: 2-6) days); non-invasive ventilation in 19.3% (median 3 (IQR: 2-5) days); and mechanical ventilation in 10.2% (median 5 (IQR: 3-7) days). Intensive care unit admission was required by 17.9% of infants (median 6 days (IQR: 2-8) days). Median overall hospital length of stay (LOS) was 5 (IQR: 3-8) days. Hospital resource use was similar across wGA groups except for overall LOS, which was shortest in those born 35 wGA (median 3 vs. 4-6 days for 32-34 wGA; P < 0.001). Strategies to reduce the burden of RSVH in otherwise healthy 32-35 wGA infants are indicated.

Isolation and characterization of denitrifiers from woodchip bioreactors for bioaugmentation application.

AIMS: This study was done to obtain denitrifiers that could be used for bioaugmentation in woodchip bioreactors to remove nitrate from agricultural subsurface drainage water. METHODS AND RESULTS: We isolated denitrifiers from four different bioreactors in Minnesota, and characterized the strains by measuring their denitrification rates and analysing their whole genomes. A total of 206 bacteria were isolated from woodchips and thick biofilms (bioslimes) that formed in the bioreactors, 76 of which were able to reduce nitrate at 15°C. Among those, nine potential denitrifying strains were identified, all of which were isolated from the woodchip samples. Although many nitrate-reducing strains were isolated from the bioslime samples, none were categorized as denitrifiers but instead as carrying out dissimilatory nitrate reduction to ammonium. CONCLUSIONS: Among the denitrifiers confirmed by 15 N stable isotope analysis and genome analysis, Cellulomonas cellasea strain WB94 and Microvirgula aerodenitrificans strain BE2.4 appear to be promising for bioreactor bioaugmentation due to their potential for both aerobic and anaerobic denitrification, and the ability of strain WB94 to degrade cellulose. SIGNIFICANCE AND IMPACT OF THE STUDY: Denitrifiers isolated in this study could be useful for bioaugmentation application to enhance nitrate removal in woodchip bioreactors.

How can nanotechnology help to combat COVID-19? Opportunities and urgent need.

Incidents of viral outbreaks have increased at an alarming rate over the past decades. The most recent human coronavirus known as COVID-19 (SARS-CoV-2) has already spread around the world and shown R0 values from 2.2 to 2.68. However, the ratio between mortality and number of infections seems to be lower in this case in comparison to other human coronaviruses (such as severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV)). These outbreaks have tested the limits of healthcare systems and have posed serious questions about management using conventional therapies and diagnostic tools. In this regard, the use of nanotechnology offers new opportunities for the development of novel strategies in terms of prevention, diagnosis and treatment of COVID-19 and other viral infections. In this review, we discuss the use of nanotechnology for COVID-19 virus management by the development of nano-based materials, such as disinfectants, personal protective equipment, diagnostic systems and nanocarrier systems, for treatments and vaccine development, as well as the challenges and drawbacks that need addressing.

Impact of apolipoprotein E genetic polymorphisms on liver disease: An essential review.

Cirrhosis is an advanced stage of liver disease, compromising liver function with systemic health implications and poor quality of life. Hepatitis C virus (HCV) infection and alcoholic liver disease are the main causes of this pathology. However, since genetic factors may play a large role in the progression and severity of liver disease, and as apolipoprotein E (apoE) has been recognised to be mainly synthesised in the liver, apoE polymorphism studies are important to better understand the causal mechanisms in liver diseases. In this review, we summarise up-to-date studies addressing how apoE polymorphisms influence liver cirrhosis and liver transplantation outcomes and potential protective mechanisms. Although more clinical studies are needed to support these findings, the apoE ɛ4 allele seems to be protective against the progression of liver cirrhosis in the majority of aetiologies and the postoperative serum apoE phenotype of the transplanted subject receptors was converted to that of the donor, indicating that >90% of apoE in plasma is synthesised in the hepatic system.

Structure and evolution of ENTH and VHS/ENTH-like domains in tepsin.

Tepsin is currently the only accessory trafficking protein identified in adaptor-related protein 4 (AP4)-coated vesicles originating at the trans-Golgi network (TGN). The molecular basis for interactions between AP4 subunits and motifs in the tepsin C-terminus have been characterized, but the biological role of tepsin remains unknown. We determined X-ray crystal structures of the tepsin epsin N-terminal homology (ENTH) and VHS/ENTH-like domains. Our data reveal unexpected structural features that suggest key functional differences between these and similar domains in other trafficking proteins. The tepsin ENTH domain lacks helix0, helix8 and a lipid binding pocket found in epsin1/2/3. These results explain why tepsin requires AP4 for its membrane recruitment and further suggest ENTH domains cannot be defined solely as lipid binding modules. The VHS domain lacks helix8 and thus contains fewer helices than other VHS domains. Structural data explain biochemical and biophysical evidence that tepsin VHS does not mediate known VHS functions, including recognition of dileucine-based cargo motifs or ubiquitin. Structural comparisons indicate the domains are very similar to each other, and phylogenetic analysis reveals their evolutionary pattern within the domain superfamily. Phylogenetics and comparative genomics further show tepsin within a monophyletic clade that diverged away from epsins early in evolutionary history (~1500 million years ago). Together, these data provide the first detailed molecular view of tepsin and suggest tepsin structure and function diverged away from other epsins. More broadly, these data highlight the challenges inherent in classifying and understanding protein function based only on sequence and structure.

Local control, safety, and survival following image-guided percutaneous microwave thermal ablation in primary lung malignancy.

AIM: To determine local control, safety, and survival following percutaneous computed tomography (CT)-guided high-power microwave ablation (MWA) in the treatment of primary lung malignancy at a single institution. MATERIAL AND METHODS: From July 2010 to June 2016, 52 patients (mean age 76.3 years, range 55-91 years) with 61 unresectable primary lung cancers of mean diameter 23.8 mm (range 26-55 mm) underwent MWA in 55 ablation sessions. Tumours were diagnosed at biopsy, or positron-emission tomography (PET) avidity (mean SUV max = 10.51) and interval growth. Statistical analysis was performed by Kaplan-Meier modelling and Cox and logistic regression. RESULTS: Local tumour progression (LTP) was diagnosed in six lesions (10%). Median time to local recurrence was 3 months (range 2-14 months). There was a near 12-fold increased odds of local recurrence if the lesion size was >3 cm (95% confidence interval [CI]: 1.84-75.14; p=0.009). The median inpatient stay was 1 day, with no intra-procedural deaths and a 0% 30-day post-ablation mortality rate. Pneumothorax requiring drain was the most serious complication, occurring in 22% (n=12) of patients. Presence of severe emphysema and predicted forced expiratory volume in 1 second (FEV1) of <50% were found to predict future requirement of a drain (odds ratio [OR] 8.17, 95% CI: 1.62-41.37, p=0.01 and OR: 5.14, 95% CI: 1.28-20.68, p=0.02 respectively), when adjusted for age and gender. Tumour size >3 cm had a hazard ratio of 4.37 compared with tumour size ≤3 cm (95% CI: 1.45-13.17, p=0.009) of risk of cancer death at any time, by Cox regression. CONCLUSION: MWA for primary lung malignancy is a safe and effective treatment for primary lung tumours with outcomes that may be comparable to stereotactic body radiation therapy.

Erratum: Rotationally Cold OH

This corrects the article DOI: 10.1103/PhysRevLett.119.073001.

Trends in rotavirus from 2001 to 2015 in two paediatric hospitals in Atlanta, Georgia.

We compared rotavirus detection patterns before (2001-2006) and after (2008-2015) rotavirus vaccine introduction. We also compared rotavirus detection patterns in odd (2009, 2011, 2013, 2015) and even (2008, 2010, 2012, 2014) years post-vaccine separately. Results of stool rotavirus antigen testing from inpatient, outpatient and emergency department encounters from July 2000 to July 2015 at two paediatric hospital laboratories in Atlanta, Georgia were reviewed. Post-vaccine, rotavirus detection declined (30.2% vs. 13.7% (overall 54.6% decline, P <0.001)), occurred more frequently outside the rotavirus season (19.8% vs. 3.5%; P < 0.001), and was more common among older children (26 vs. 13 median months of age; P < 0.001). During odd years post-vaccine, rotavirus detection was significantly higher than even years (20.2% vs. 6.4%; P < 0.001). Rotavirus detection declined substantially and developed a biennial pattern in the post-vaccine era. The intensity and temporality of rotavirus detection in odd years post-vaccine resembled that observed pre-vaccine, although considerably reduced in magnitude.

Administration of vorinostat disrupts HIV-1 latency in patients on antiretroviral therapy.

Despite antiretroviral therapy, proviral latency of human immunodeficiency virus type 1 (HIV-1) remains a principal obstacle to curing the infection. Inducing the expression of latent genomes within resting CD4(+) T cells is the primary strategy to clear this reservoir. Although histone deacetylase inhibitors such as suberoylanilide hydroxamic acid (also known as vorinostat, VOR) can disrupt HIV-1 latency in vitro, the utility of this approach has never been directly proven in a translational clinical study of HIV-infected patients. Here we isolated the circulating resting CD4(+) T cells of patients in whom viraemia was fully suppressed by antiretroviral therapy, and directly studied the effect of VOR on this latent reservoir. In each of eight patients, a single dose of VOR increased both biomarkers of cellular acetylation, and simultaneously induced an increase in HIV RNA expression in resting CD4(+) cells (mean increase, 4.8-fold). This demonstrates that a molecular mechanism known to enforce HIV latency can be therapeutically targeted in humans, provides proof-of-concept for histone deacetylase inhibitors as a therapeutic class, and defines a precise approach to test novel strategies to attack and eradicate latent HIV infection directly.

Evaluation of a single-pass with biphasic intravenous contrast medium injection CT protocol for the assessment of complications post-simultaneous pancreas-kidney transplant.

AIM: To evaluate the use of a single-pass with biphasic intravenous contrast medium injection computed tomography (CT) protocol to provide diagnostic quality CT studies for the assessment of complications post-simultaneous pancreas-kidney transplant (SPK). MATERIALS AND METHODS: This was an audit of practice and the need for informed consent was waived. The protocol was used in consecutive patients undergoing CT to exclude intra-abdominal sepsis post-SPK between June and December 2015. Single CT acquisition of the abdomen and pelvis was initiated 70 seconds after the start of biphasic contrast medium injection (66 ml at 1.2 ml/s, followed by 34 ml at 2.4 ml/s, 370 mg iodine/ml). The named transplant pancreas vessels were identified and the attenuation values of the blood within were measured. Diagnostic quality was confirmed if values were >211 HU and >80 HU in the arteries and veins, respectively. RESULTS: Thirteen CT studies were performed in 10 patients. CT studies were excluded due to complete pancreatic necrosis, and transplant superior mesenteric artery (SMA) thrombus with pancreatic head ischaemia causing effacement of the transplant superior mesenteric vein (SMV). Diagnostic quality of the analysed CT studies were confirmed with mean attenuation value of blood >211 HU in the transplant pancreatic arteries (SMA=259.0±51.4 HU, splenic artery=245.3±37.5 HU), and >80 HU in the pancreatic veins (SMV=195.4±36.2 HU, splenic vein=185.1±54.2 HU). CONCLUSION: Diagnostic quality CT studies were obtained using the single-pass CT protocol. Radiation exposure to patients may be reduced with this protocol, while permitting simultaneous assessment of parenchymal and vascular complications post-SPK.

Precision determination of absolute neutron flux.

A technique for establishing the total neutron rate of a highly-collimated monochromatic cold neutron beam was demonstrated using an alpha-gamma counter. The method involves only the counting of measured rates and is independent of neutron cross sections, decay chain branching ratios, and neutron beam energy. For the measurement, a target of 10B-enriched boron carbide totally absorbed the neutrons in a monochromatic beam, and the rate of absorbed neutrons was determined by counting 478 keV gamma rays from neutron capture on 10B with calibrated high-purity germanium detectors. A second measurement based on Bragg diffraction from a perfect silicon crystal was performed to determine the mean de Broglie wavelength of the beam to a precision of 0.024%. With these measurements, the detection efficiency of a neutron monitor based on neutron absorption on 6Li was determined to an overall uncertainty of 0.058%. We discuss the principle of the alpha-gamma method and present details of how the measurement was performed including the systematic effects. We also describe how this method may be used for applications in neutron dosimetry and metrology, fundamental neutron physics, and neutron cross section measurements.