Effect of Extreme Variations of Fundamental Constants on the Structure of Atoms and Molecules.

The fundamental constants (FCs) of physics are promoted to dynamic quantities in modern theories. So far most of the literature focused on small fractional variations in the values of FCs. In this paper, we investigate the novel regime of extreme but transient variations of FCs. We focus on the speed of light (c) and show that its variation can dramatically change the electronic structure and chemistry of atoms and molecules. These changes are induced by increased relativistic effects when c is reduced from its nominal value. To model these changes, we solve the fully relativistic Dirac equation at different values of c. We show that at extreme variations of c, the periodic table is truncated, the nominal ground states of atoms can change, water fails to serve as a universal solvent, and the ammonia molecule becomes planar.

Feasibility of wearable monitors to detect heart rate variability in children with hand, foot and mouth disease.

Hand foot and mouth disease (HFMD) is caused by a variety of enteroviruses, and occurs in large outbreaks in which a small proportion of children deteriorate rapidly with cardiopulmonary failure. Determining which children are likely to deteriorate is difficult and health systems may become overloaded during outbreaks as many children require hospitalization for monitoring. Heart rate variability (HRV) may help distinguish those with more severe diseases but requires simple scalable methods to collect ECG data.We carried out a prospective observational study to examine the feasibility of using wearable devices to measure HRV in 142 children admitted with HFMD at a children's hospital in Vietnam. ECG data were collected in all children. HRV indices calculated were lower in those with enterovirus A71 associated HFMD compared to those with other viral pathogens.HRV analysis collected from wearable devices is feasible in a low and middle income country (LMIC) and may help classify disease severity in HFMD.

Emerging Enterovirus A71 Subgenogroup B5 Causing Severe Hand, Foot, and Mouth Disease, Vietnam, 2023.

We report on a 2023 outbreak of severe hand, foot, and mouth disease in southern Vietnam caused by an emerging lineage of enterovirus A71 subgenogroup B5. Affected children were significantly older than those reported during previous outbreaks. The virus should be closely monitored to assess its potential for global dispersal.

Laparoscopic retroperitoneal heminephrectomy for renal cell carcinoma in horseshoe kidney: a case report and review of the literature.

INTRODUCTION: In this case report, we demonstrate our technique of a retroperitoneal laparoscopic heminephrectomy for a T1b right hilar tumor in a horseshoe kidney. CASE PRESENTATION: A 77-year-old Vietnamese woman presented to the hospital because of right flank pain. On presentation, her serum creatinine was 0.86 mg/dL and glomerular filtration rate was 65.2 mL/minute/1.73 m2. According to her renal scintigraphy, glomerular filtration rates of the right and left moieties were 24.2 and 35.5 mL/minute, respectively. Computed tomography imaging demonstrated a 5.5 × 5.0 cm solid hilar mass with a cT1bN0M0 tumor stage was in the right moiety. After discussion, the patient elected a minimally invasive surgery to treat her malignancy. The patient was placed in a flank position. We used Gaur's balloon technique to create the retroperitoneal working space, and four trocar ports were planned for operation. Three arteries were dissected, including two arteries feeding the right moiety, one artery feeding the isthmus, and one vein, which was clipped and divided by Hem-o-lok. The isthmusectomy was performed with an Endostapler. Consequently, the ureter was clipped and divided. Finally, the whole right segment of the horseshoe kidney was mobilized and taken out via the flank incision. RESULTS: The total operative time was 250 min with an estimated blood loss of 200 mL. The patient's serum creatinine after surgery was 1.08 mg/dL, and glomerular filtration rate was 49.47 mL/minute/1.73 m2. The patient was discharged on postoperative day #4 without complication. Final pathologic examination of the tumor specimen revealed a Fuhrman grade II clear cell renal cell carcinoma, capsular invasion, with negative surgical margins. After a three-month follow-up, the serum creatinine was 0.95 mg/dL, and glomerular filtration rate was 57.7 mL/minute/1.73 m2. Local recurrence or metastasis was not detected by follow-up computed tomography imaging. CONCLUSIONS: Retroperitoneal laparoscopic heminephrectomy is a safe and feasible technique for patients with renal cell carcinoma in a horseshoe kidney and may be particularly useful in low income settings without access to robotic technology.

Antimony Compounds Associate with Atopic Dermatitis and Influence Models of Itch and Dysbiosis.

Compared to the myriad of known triggers for rhinitis and asthma, environmental exposure research for atopic dermatitis (AD) is not well established. We recently reported that an untargeted search of U.S. Environmental Protection Agency (EPA) databases versus AD rates by United States (U.S.) postal codes revealed that isocyanates, such as toluene diisocyanate (TDI), are the pollutant class with the strongest spatiotemporal and epidemiologic association with AD. We further demonstrated that (di)isocyanates disrupt ceramide-family lipid production in commensal bacteria and activate the thermo-itch host receptor TRPA1. In this report, we reanalyzed regions of the U.S. with low levels of diisocyanate pollution to assess if a different chemical class may contribute. We identified antimony compounds as the top associated pollutant in such regions. Exposure to antimony compounds would be expected from brake dust in high-traffic areas, smelting plants, bottled water, and dust from aerosolized soil. Like TDI, antimony inhibited ceramide-family lipid production in Roseomonas mucosa and activated TRPA1 in human neurons. While further epidemiologic research will be needed to directly evaluate antimony exposure with surrounding AD prevalence and severity, these data suggest that compounds which are epidemiologically associated with AD, inhibit commensal lipid production, and activate TRPA1 may be causally related to AD pathogenesis.

Spatiotemporal Evolution of SARS-CoV-2 Alpha and Delta Variants during Large Nationwide Outbreak of COVID-19, Vietnam, 2021.

We analyzed 1,303 SARS-CoV-2 whole-genome sequences from Vietnam, and found the Alpha and Delta variants were responsible for a large nationwide outbreak of COVID-19 in 2021. The Delta variant was confined to the AY.57 lineage and caused >1.7 million infections and >32,000 deaths. Viral transmission was strongly affected by nonpharmaceutical interventions.

Evolution of a System to Monitor Infant Neuromotor Development in the Home: Lessons from COVID-19.

In the nine months leading up to COVID-19, our biomedical engineering research group was in the very early stages of development and in-home testing of HUGS, the Hand Use and Grasp Sensor (HUGS) system. HUGS was conceived as a tool to allay parents' anxiety by empowering them to monitor their infants' neuromotor development at home. System focus was on the evolving patterns of hand grasp and general upper extremity movement, over time, in the naturalistic environment of the home, through analysis of data captured from force-sensor-embedded toys and 3D video as the baby played. By the end of March, 2020, as the COVID-19 pandemic accelerated and global lockdown ensued, home visits were no longer possible and HUGS system testing ground to an abrupt halt. In the spring of 2021, still under lockdown, we were able to resume recruitment and in-home testing with HUGS-2, a system whose key requirement was that it be contactless. Participating families managed the set up and use of HUGS-2, supported by a detailed library of video materials and virtual interaction with the HUGS team for training and troubleshooting over Zoom. Like the positive/negative poles of experience reported by new parents under the isolation mandated to combat the pandemic, HUGS research was both impeded and accelerated by having to rely solely on distance interactions to support parents, troubleshoot equipment, and securely transmit data. The objective of this current report is to chronicle the evolution of HUGS. We describe a system whose design and development straddle the pre- and post-pandemic worlds of family-centered health technology design. We identify and classify the clinical approaches to infant screening that predominated in the pre-COVID-19 milieu and describe how these procedural frameworks relate to the family-centered conceptualization of HUGS. We describe how working exclusively through the proxy of parents revealed the family's priorities and goals for child interaction and surfaced HUGS design shortcomings that were not evident in researcher-managed, in-home testing prior to the pandemic.

Urinary catecholamine excretion, cardiovascular variability, and outcomes in tetanus.

Severe tetanus is characterized by muscle spasm and cardiovascular system disturbance. The pathophysiology of muscle spasm is relatively well understood and involves inhibition of central inhibitory synapses by tetanus toxin. That of cardiovascular disturbance is less clear, but is believed to relate to disinhibition of the autonomic nervous system. The clinical syndrome of autonomic nervous system dysfunction (ANSD) seen in severe tetanus is characterized principally by changes in heart rate and blood pressure which have been linked to increased circulating catecholamines. Previous studies have described varying relationships between catecholamines and signs of ANSD in tetanus, but are limited by confounders and assays used. In this study, we aimed to perform detailed characterization of the relationship between catecholamines (adrenaline and noradrenaline), cardiovascular parameters (heart rate and blood pressure) and clinical outcomes (ANSD, mechanical ventilation required, and length of intensive care unit stay) in adults with tetanus, as well as examine whether intrathecal antitoxin administration affected subsequent catecholamine excretion. Noradrenaline and adrenaline were measured by ELISA from 24-h urine collections taken on day 5 of hospitalization in 272 patients enrolled in a 2 × 2 factorial-blinded randomized controlled trial in a Vietnamese hospital. Catecholamine results measured from 263 patients were available for analysis. After adjustment for potential confounders (i.e., age, sex, intervention treatment, and medications), there were indications of non-linear relationships between urinary catecholamines and heart rate. Adrenaline and noradrenaline were associated with subsequent development of ANSD, and length of ICU stay.

Prehistoric pathways to Anthropocene adaptation: Evidence from the Red River Delta, Vietnam.

Over the past twenty years, government advisory bodies have placed increasing emphasis on the need for adaptive measures in response to the effects of human-induced climate change. Integrated Assessment Models (IAMs), which incorporate macroeconomic and climate variables, feature prominently in advisory content, though they rarely draw on data from outside strictly constrained hypothetical systems. This has led to assertions that they are not well-suited to approximate complex systemic human-environment processes. Modular, interdisciplinary approaches have offered a way to address this shortcoming; however, beyond climate records, prehistoric data continue to be under-utilised in developing such models. In this paper we highlight the contribution that archaeology and palaeoecology can make to the development of the next generation IAMs that are expected to enhance provision for more local and pro-active adaptations to future climate change. We present data from one of Southeast Asia's most heavily developed river deltas: the Red River (Song Hong) Delta, in Vietnam and localised analysis from the Tràng An Landscape Complex World Heritage Site, on the delta's southern margin. Comparison is made between Shared Socio-economic Pathways (SSP) 5-8.5 and SSP2-4.5 emission projection models and the Mid-Holocene inundation of the Red River Basin. We highlight the value to taking a scientific long view of coastal evolution through an illustrative set of eight research foci where palaeo-data can bring new and localised empirical data to bear on future risk management planning. We proceed to demonstrate the applicability of palaeoenvironmental, zooarchaeological and historical evidence to management and the development of sustainable conservation strategies using Tràng An as a case study. In so doing, we further highlight the importance of knowledge exchange between scientific, corporate, non-governmental, local, and state stakeholders to achieve tangible results on the ground.

Seroprotection against tetanus in southern Vietnam.

BACKGROUND: Ongoing tetanus cases and sporadic outbreaks of vaccine-preventable diseases associated with routine vaccination programmes remain problems in many low and middle-income countries, including Vietnam. With no human-to-human transmission or natural immunity, tetanus antibody levels indicate both individual risk of tetanus and gaps in vaccination programmes. METHODS: To investigate gaps in immunity to tetanus in Vietnam, a country with a historically high level of tetanus vaccination coverage, tetanus antibodies were measure by ELISA from samples selected from a long-term serum bank, established for the purposes of general-population seroepidemiological investigations in southern Vietnam. Samples were selected from 10 provinces, focussing on age-groups targeted by national vaccination programmes for infants and pregnant women (Expanded Programme on Immunization, EPI, and Maternal and Neonatal Tetanus, MNT). RESULTS: Antibodies were measured from a total of 3864 samples. Highest tetanus antibody concentrations occurred in children under 4 years old, over 90 % of whom had protective levels. Approximately 70 % of children aged 7-12 years had protective antibody concentrations although there was variation among provinces. For infants and children, there were no significant differences in tetanus protection between males and females, but for adults aged 20-35 years, in five of the ten provinces surveyed, protection against tetanus was higher in females (p < 0.05) who are eligible for booster doses under the MNT programme. In seven of ten provinces, antibody concentrations were inversely related to age (p < 0.01) and protection of older individuals was generally low. CONCLUSION: Widespread immunity to tetanus toxoid is seen in infants and young children consistent with the high coverage rates reported for diptheria tetanus toxoid and pertussis (DTP) in Vietnam. However, the lower antibody concentrations seen in older children and men suggest reduced immunity to tetanus in populations not targeted by EPI and MNT programmes.

Monkeypox Virus Infection in 2 Female Travelers Returning to Vietnam from Dubai, United Arab Emirates, 2022.

Mpox was diagnosed in 2 women returning to Vietnam from the United Arab Emirates. The monkeypox viruses belonged to an emerging sublineage, A.2.1, distinct from B.1, which is responsible for the ongoing multicountry outbreak. Women could contribute to mpox transmission, and enhanced genomic surveillance is needed to clarify pathogen evolution.

Kinetics of Neutralizing Antibodies against Omicron Variant in Vietnamese Healthcare Workers after Primary Immunization with ChAdOx1-S and Booster Immunization with BNT162b2.

We studied the development and persistence of neutralizing antibodies against SARS-CoV-2 ancestral strain, and Delta and Omicron (BA.1 and BA.2) variants in Vietnamese healthcare workers (HCWs) up to 15 weeks after booster vaccination. We included 47 HCWs, including group 1 (G1, N = 21) and group 2 (G2; N = 26) without and with breakthrough Delta variant infection before booster immunization, respectively). The study participants had completed primary immunization with ChAdOx1-S and booster vaccination with BNT162b2. Neutralizing antibodies were measured using a surrogate virus neutralization assay. Of the 21 study participants in G1, neutralizing antibodies against ancestral strain, Delta variant, BA.1, and BA.2 were (almost) abolished at month 8 after the second dose, but all had detectable neutralizing antibodies to the study viruses at week 2 post booster dose. Of the 26 study participants in G2, neutralizing antibody levels to BA.1 and BA.2 were significantly higher than those to the corresponding viruses measured at week 2 post breakthrough infection and before the booster dose. At week 15 post booster vaccination, neutralizing antibodies to BA.1 and BA.2 dropped significantly, with more profound changes observed in those without breakthrough Delta variant infection. Booster vaccination enhanced neutralizing activities against ancestral strain and Delta variant compared with those induced by primary vaccination. These responses were maintained at high levels for at least 15 weeks. Our findings emphasize the importance of the first booster dose in producing cross-neutralizing antibodies against Omicron variant. A second booster to maintain long-term vaccine effectiveness against the currently circulating variants merits further research.

Development of optimized protocol for culturing African swine fever virus field isolates in MA104 cells.

The goal of this study was to identify a candidate commercial cell line for the replication of African swine fever virus (ASFV) by comparing several available cell lines with various medium factors. In the sensitivity test of cells, MA104 and MARC-145 had strong potential for ASFV replication. Next, MA104 cells were used to compare the adaptation of ASFV obtained from tissue homogenates and blood samples in various infectious media. At the 10th passage, the ASFV obtained from the blood sample had a significantly higher viral load than that obtained from the tissue sample (P = 0.000), exhibiting a mean cycle threshold (Ct) value = 20.39 ± 1.99 compared with 25.36 ± 2.11. For blood samples, ASFV grew on infectious medium B more robustly than on infectious medium A (P = 0.006), corresponding to a Ct value = 19.58 ± 2.10 versus 21.20 ± 1.47. African swine fever virus originating from blood specimens continued to multiply gradually and peaked in the 15th passage, exhibiting a Ct value = 14.36 ± 0.22 in infectious medium B and a Ct value = 15.42 ± 0.14 in infectious medium A. When ASFV was cultured from tissue homogenates, however, there was no difference (P = 0.062) in ASFV growth between infectious media A and B. A model was developed to enhance ASFV replication through adaptation to MA104 cells. The lack of mutation at the genetic segments encoding p72, p54, p30, and the central hypervariable region (CVR) in serial culture passages is important in increasing the probability of maintaining immunogenicity when developing a vaccine candidate.

L'objectif de cette étude était d'identifier une lignée cellulaire commerciale candidate pour la réplication du virus de la peste porcine africaine (ASFV) en comparant plusieurs lignées cellulaires disponibles et différents milieux. Lors du test de sensibilité des cellules, MA104 et MARC-145 présentaient un fort potentiel pour la réplication d'AFSV. Par la suite, les cellules MA104 ont été utilisées pour comparer l'adaptation d'ASFV obtenu d'homogénats de tissus et d'échantillons de sang dans différents milieux. Au dixième passage, l'ASFV obtenu de l'échantillon de sang avait une charge virale significativement plus élevée que celle obtenue de l'échantillon de tissu (P = 0,000), avec une valeur seuil moyenne de cycles (Ct) de 20,39 ± 1,99 comparativement à 25,36 ± 2,11. Pour les échantillons sanguins, l'ASFV a poussé sur le milieu B de manière plus robuste que sur le milieu A (P = 0,006), ce qui correspond à une valeur Ct de 19,58 ± 2,10 versus 21,20 ± 1,47. L'ASFV provenant des échantillons sanguins continua de se multiplier graduellement et atteignit un pic au 15e passage, avec une valeur Ct de 14,36 ± 0,22 dans le milieu B et une valeur Ct de 15,42 ± 0,14 dans le milieu A. Toutefois, lorsque l'ASFV fut cultivé à partir des homogénats de tissus, il n'y avait pas de différence (P = 0,062) dans la croissance d'ASFV entre les milieux A et B. Un modèle a été développé pour augmenter la réplication d'ASFV par adaptation aux cellules MA104. L'absence de mutation au segment génétique codant pour p72, p54, p30, et la région hypervariable centrale (CVR) dans des passages en série en culture est importante en augmentant la probabilité de maintenir une immunogénicité lors du développement d'un vaccin candidat.(Traduit par Docteur Serge Messier).

Kinetics of neutralising antibodies against Omicron variant in Vietnamese healthcare workers after primary immunisation with ChAdOx1-S and booster with BNT162b2

We studied the development and persistence of neutralising antibodies against SARS-CoV-2 ancestral strain, and Delta and Omicron (BA.1 and BA.2) variants in Vietnamese healthcare workers (HCWs) up to 15 weeks after booster vaccination. We included 47 HCWs with different pre-existing immune statuses (group 1 (G1): n=21, and group 2 (G2): n=26 without and with prior breakthrough Delta variant infection, respectively). The study participants had completed primary immunisation with ChAdOx1-S and booster vaccination with BNT162b2. Neutralising antibodies were measured using a surrogate virus neutralisation assay. Of the 21 study participants in G1, neutralising antibodies against ancestral strain, Delta variant, BA.1 and BA.2 were (almost) abolished at month 8 after the second dose, but all had detectable neutralising antibodies to the study viruses at week two post booster dose. Of the 26 study participants in G2, neutralising antibody levels to BA.1 and BA.2 were significantly higher than those to the corresponding viruses measured at week 2 post breakthrough infection and before the booster dose. At week 15 post booster vaccination, neutralising antibodies to BA.1 and BA.2 dropped significantly, with more profound changes observed in those without breakthrough Delta variant infection. Booster vaccination enhanced neutralising activities against ancestral strain and Delta variant, as compared to those induced by primary vaccination. These responses were maintained at high levels for at least 15 weeks. Our findings emphasise the importance of the first booster dose in producing cross-neutralising antibodies against Omicron variant. A second booster dose might be needed to maintain long-term protection against Omicron variant.

Use of Septal Cartilage in Rhinoplasty to Correct Nasal Deformity After Unilateral Cleft Lip and Palate Surgery.

Background: The most common facial defect is the congenital cleft lip (CL), which can occur with or without a cleft palate (CP). Patients need primary plastic surgery for rehabilitation and esthetics; nevertheless, secondary abnormalities of the lip and nose may develop after primary surgery. These deformities are complex and involve all tissue layers, including the skeletal platform, inner lining, osseocartilaginous structure, and overlying skin. This study evaluated the results of nasal deformity rhinoplasty using septal cartilage in patients with nasal deformities after plastic surgery for unilateral CL and CP. Methods: This retrospective study was conducted on 21 patients with secondary unilateral CL nasal deformity between June 2015 and August 2016. All patients underwent rhinoplasty with the use of septal cartilage grafts. Pre- and post-operative nasal forms were measured. Results: The patients had cosmetic problems and impaired nasal airflow due to distorted anatomy. The postoperative nasal forms were improved in all patients. Rhinoplasty using septal cartilage effectively increased the height of the columella and nose and improved the balance of the base width and the length of both sides of the nose. Excellent results were achieved in 18 patients. Three patients showed good results. No patient showed a fair result. Conclusion: This study demonstrated an effective correction of esthetic deformities and significant improvement in airway patency. A long-term longitudinal study is still required to evaluate the influence of septal cartilage harvesting on face and nasal development until children reach their late teens.

Immunogenicity of Oxford-AstraZeneca COVID-19 Vaccine in Vietnamese Health-Care Workers.

We studied the immunogenicity of the Oxford-AstraZeneca vaccine in health-care workers of a major infectious diseases hospital in Vietnam. We measured neutralizing antibodies before and 14 days after each dose, and at day 28 and month 3 after dose 1. A total of 554 workers (136 men and 418 women; age range, 22-71 years; median age, 36 years) participated with the study. Of the 144 participants selected for follow-up after dose 1, 104 and 94 gave blood for antibody measurement at weeks 6 and 8, and at month 3 after dose 1, respectively. The window time between the two doses was 6 weeks. At baseline, none had detectable neutralizing antibodies. After dose 1, the proportion of participants with detectable neutralizing antibodies increased from 27.3% (151 of 554) at day 14 to 78.0% (432 of 554) at day 28. Age correlated negatively with the development and the levels of neutralizing antibodies. However, at day 28, these differences were less profound, and women had a greater seroconversion rate and greater levels of neutralizing antibodies than men. After dose 2, these age and gender associations were not observable. In addition, the proportion of study participants with detectable neutralizing antibodies increased from 70.2% (73 of 104) before dose 2 (week 6, after dose 1) to 98.1% (102 of 104) 14 days later. At month 3, neutralizing antibodies decreased and 94.7% (89 of 94) of the study participants remained seropositive. The Oxford-AstraZeneca COVID-19 vaccine is immunogenic in Vietnamese health-care workers. These data are critical to informing the deployment of the COVID-19 vaccine in Vietnam and in Southeast Asia, where vaccination coverage remains inadequate.

Characteristics of obstructive sleep apnea syndrome in patients with partial laryngectomy.

OBJECTIVES: The impacts of partial laryngectomy on sleep-disordered breathing were rarely investigated and reported in a limited number of patients. The aim of this study was to assess the prevalence of obstructive sleep apnea-hypopnea syndrome (OSAHS) in patients with partial laryngectomy. STUDY DESIGN: Case series. METHODS: All patients undergoing partial laryngectomy by open approach (frontolateral vertical partial laryngectomy and supracricoid horizontal partial laryngectomy) for squamous cell carcinoma of the larynx between January 2006 and December 2019 were enrolled. Listed patients were contacted via telephone to propose participating in the study and plan a sleep study: self-assessments of sleep quality using the Pittsburgh Sleep Quality Index (PSQI) following a home sleep recording using respiratory polygraphy. Daytime sleepiness was also self-assessed by using the Epworth sleepiness scale. RESULTS: Twenty patients with sleep record were included to the analyses. There were 11/20 patients (55%) diagnosed with moderate to severe OSASH. No relationship between OSAHS severity and age as well as body mass index (BMI) was observed. The Epworth sleepiness score was not necessarily high in patients with moderate/severe OSASH. Type of partial laryngectomy did not influence apnea-hypopnea index (AHI) results. There was no difference in terms of age, BMI, gender, type of partial laryngectomy, and the presence of adjuvant radiotherapy between two groups AHI < 15/h and AHI ≥ 15/h. CONCLUSION: A sleep study screening for OSAHS should be considered in patients with partial laryngectomy in order to improve their sleep quality and quality of life even though they did not exhibit daily sleepiness and obesity.

An observational study of breakthrough SARS-CoV-2 Delta variant infections among vaccinated healthcare workers in Vietnam.

BACKGROUND: Data on breakthrough SARS-CoV-2 Delta variant infections in vaccinated individuals are limited. METHODS: We studied breakthrough infections among Oxford-AstraZeneca vaccinated healthcare workers in an infectious diseases hospital in Vietnam. We collected demographic and clinical data alongside serial PCR testing, measurement of SARS-CoV-2 antibodies, and viral whole-genome sequencing. FINDINGS: Between 11th-25th June 2021 (7-8 weeks after the second dose), 69 staff tested positive for SARS-CoV-2. 62 participated in the study. Most were asymptomatic or mildly symptomatic and all recovered. Twenty-two complete-genome sequences were obtained; all were Delta variant and were phylogenetically distinct from contemporary viruses obtained from the community or from hospital patients admitted prior to the outbreak. Viral loads inferred from Ct values were 251 times higher than in cases infected with the original strain in March/April 2020. Median time from diagnosis to negative PCR was 21 days (range 8-33). Neutralizing antibodies (expressed as percentage of inhibition) measured after the second vaccine dose, or at diagnosis, were lower in cases than in uninfected, fully vaccinated controls (median (IQR): 69.4 (50.7-89.1) vs. 91.3 (79.6-94.9), p=0.005 and 59.4 (32.5-73.1) vs. 91.1 (77.3-94.2), p=0.002). There was no correlation between vaccine-induced neutralizing antibody levels and peak viral loads or the development of symptoms. INTERPRETATION: Breakthrough Delta variant infections following Oxford-AstraZeneca vaccination may cause asymptomatic or mild disease, but are associated with high viral loads, prolonged PCR positivity and low levels of vaccine-induced neutralizing antibodies. Epidemiological and sequence data suggested ongoing transmission had occurred between fully vaccinated individuals. FUNDING: Wellcome and NIH/NIAID.

Atomic Ionization by Scalar Dark Matter and Solar Scalars.

We calculate the cross sections of atomic ionization by absorption of scalar particles in the energy range from a few eV to 100 keV. We consider both nonrelativistic particles (dark matter candidates) and relativistic particles that may be produced inside the Sun. We provide numerical results for atoms relevant for direct dark matter searches (O, Na, Ar, Ca, Ge, I, Xe, W and Tl). We identify a crucial flaw in previous calculations and show that they overestimated the ionization cross sections by several orders of magnitude due to violation of the orthogonality of the bound and continuum electron wave functions. Using our computed cross sections, we interpret the recent data from the Xenon1T experiment, establishing the first direct bounds on coupling of scalars to electrons. We argue that the Xenon1T excess can be explained by the emission of scalars from the Sun. Although our finding is in a similar tension with astrophysical bounds as the solar axion hypothesis, we establish direct limits on scalar DM for the ∼1-10 keV mass range. We also update axio-ionization cross sections. Numerical data files are provided.