SARS-CoV-2 infections amongst personnel providing home care services for older persons in Stockholm, Sweden.

BACKGROUND: In Sweden, home care services is a major external contact for older persons. METHODS: Five home care service companies in Stockholm, Sweden, enrolled 405 employees to a study including serum IgG to SARS-CoV-2 and SARS-CoV-2 virus in throat swabs. RESULTS: 20.1% (81/403) of employees were seropositive, about twice as many as in a simultaneously enrolled reference population (healthcare workers entirely without patient contact, n = 3671; 9.7% seropositivity). 13/379 employees (3.4%) had a current infection (PCR positivity). Amongst these, 5 were also seropositive and 3 were positive with low amounts of virus. High amounts of virus and no antibodies (a characteristic for presymptomatic COVID-19) were present in 5 employees (1.3%). CONCLUSIONS: Personnel providing home services for older persons appear to be a risk group for SARS-CoV-2. Likely presymptomatic employees can be readily identified by screening. Increased protection of employees and of the older persons they serve is warranted.

Evidence for a spin-aligned neutron-proton paired phase from the level structure of (92)Pd.

Shell structure and magic numbers in atomic nuclei were generally explained by pioneering work that introduced a strong spin-orbit interaction to the nuclear shell model potential. However, knowledge of nuclear forces and the mechanisms governing the structure of nuclei, in particular far from stability, is still incomplete. In nuclei with equal neutron and proton numbers (N = Z), enhanced correlations arise between neutrons and protons (two distinct types of fermions) that occupy orbitals with the same quantum numbers. Such correlations have been predicted to favour an unusual type of nuclear superfluidity, termed isoscalar neutron-proton pairing, in addition to normal isovector pairing. Despite many experimental efforts, these predictions have not been confirmed. Here we report the experimental observation of excited states in the N = Z = 46 nucleus (92)Pd. Gamma rays emitted following the (58)Ni((36)Ar,2n)(92)Pd fusion-evaporation reaction were identified using a combination of state-of-the-art high-resolution γ-ray, charged-particle and neutron detector systems. Our results reveal evidence for a spin-aligned, isoscalar neutron-proton coupling scheme, different from the previous prediction. We suggest that this coupling scheme replaces normal superfluidity (characterized by seniority coupling) in the ground and low-lying excited states of the heaviest N = Z nuclei. Such strong, isoscalar neutron-proton correlations would have a considerable impact on the nuclear level structure and possibly influence the dynamics of rapid proton capture in stellar nucleosynthesis.

Fermentation of lignocellulosic hydrolysate by the alternative industrial ethanol yeast Dekkera bruxellensis.

AIM: Testing the ability of the alternative ethanol production yeast Dekkera bruxellensis to produce ethanol from lignocellulose hydrolysate and comparing it to Saccharomyces cerevisiae. METHODS AND RESULTS: Industrial isolates of D. bruxellensis and S. cerevisiae were cultivated in small-scale batch fermentations of enzymatically hydrolysed steam exploded aspen sawdust. Different dilutions of hydrolysate were tested. None of the yeasts grew in undiluted or 1:2 diluted hydrolysate [final glucose concentration always adjusted to 40 g l⁻¹ (0.22 mol l⁻¹)]. This was most likely due to the presence of inhibitors such as acetate or furfural. In 1:5 hydrolysate, S. cerevisiae grew, but not D. bruxellensis, and in 1:10 hydrolysate, both yeasts grew. An external vitamin source (e.g. yeast extract) was essential for growth of D. bruxellensis in this lignocellulosic hydrolysate and strongly stimulated S. cerevisiae growth and ethanol production. Ethanol yields of 0.42 ± 0.01 g ethanol (g glucose)⁻¹ were observed for both yeasts in 1:10 hydrolysate. In small-scale continuous cultures with cell recirculation, with a gradual increase in the hydrolysate concentration, D. bruxellensis was able to grow in 1:5 hydrolysate. In bioreactor experiments with cell recirculation, hydrolysate contents were increased up to 1:2 hydrolysate, without significant losses in ethanol yields for both yeasts and only slight differences in viable cell counts, indicating an ability of both yeasts to adapt to toxic compounds in the hydrolysate. CONCLUSIONS: Dekkera bruxellensis and S. cerevisiae have a similar potential to ferment lignocellulose hydrolysate to ethanol and to adapt to fermentation inhibitors in the hydrolysate. SIGNIFICANCE AND IMPACT OF THE STUDY: This is the first study investigating the potential of D. bruxellensis to ferment lignocellulosic hydrolysate. Its high competitiveness in industrial fermentations makes D. bruxellensis an interesting alternative for ethanol production from those substrates.

Communications: Elementary oxygen electrode reactions in the aprotic Li-air battery.

We discuss the electrochemical reactions at the oxygen electrode of an aprotic Li-air battery. Using density functional theory to estimate the free energy of intermediates during the discharge and charge of the battery, we introduce a reaction free energy diagram and identify possible origins of the overpotential for both processes. We also address the question of electron conductivity through the Li(2)O(2) electrode and show that in the presence of Li vacancies Li(2)O(2) becomes a conductor.

Retrospective analysis of one-stage maxillary sinus augmentation with endosseous implants.

The aim of the present retrospective study was to evaluate the results of a one-stage reconstructive procedure using titanium implants placed in iliac corticocancellous bone blocks grafted to the floor of maxillary sinuses. Forty-nine patients received 314 Brånemark implants, of which 171 implants of various lengths were placed in the grafted bone and 143 implants in the adjacent maxillary alveolar process (which includes 11 implants placed in onlay grafts). Five patients also received onlay grafts to the anterior maxilla. Follow-up time was 3 to 49 months after abutment connection, which was performed 9 months after implant placement. Eighty-two percent of the implants were successfully integrated in the grafted area and 84.8% in the adjacent bone. Eleven patients (22.4%) lost one to four implants or a few implants in strategic positions, requiring secondary implant placement prior to the manufacturing of fixed prostheses, whereas 35 (71.4%) received primary fixed restorations. Only two individuals (4.1%) received permanent implant-supported overdentures. Assessments of esthetics, phonetics, and function were made by the surgical-prosthodontic team and compared with those of the patients. Opinions regarding the functional outcome of treatment appeared least correlated. The total implant survival rate compares favorably with other reports.

Two-stage maxillary sinus reconstruction with endosseous implants: a prospective study.

The aim of this prospective study was to evaluate the results of 2-stage maxillary sinus reconstruction using titanium implants placed into iliac corticocancellous bone blocks previously grafted to the floor of sinuses. Fifty consecutive patients received 314 Brånemark implants of varying lengths; 202 implants were placed in the grafted bone and 112 were placed in the adjacent anterior maxillary alveolar process, which had received buccal onlay bone grafts. Follow-up time was 9 to 48 months after implant placement, which was accomplished 5 months after bone grafting. Eighty-four percent of the implants were integrated into the grafted sinuses and 75% were integrated into the anterior graft. Six patients (12%) lost implants in strategic positions, leading to secondary implant placement prior to fabrication of fixed prostheses. Thirty-eight patients (76%) received fixed prostheses. Only 5 individuals (10%) attained permanent implant-anchored overdentures. One patient lost all implants. The total implant survival rate (80.9%) and the survival rate of the fixed prostheses (100%) compare favorably with other reports.

Sensibility following sagittal split osteotomy in the mandible: a prospective clinical study.

Bilateral sagittal split osteotomy may be associated with postoperative sensory deficiency in the area innervated by the inferior alveolar nerve. The aim of this study was to assess the neurosensory response of the inferior alveolar nerve after such surgery. Fifty consecutive patients receiving mandibular setback or advancement were investigated. Four different neurosensory tests were used: light touch, pin prick, static two-point discrimination, and vibration thresholds. These tests were performed preoperatively, 2 days, as well as 3 months and 12 months postoperatively. The methodologic error was found negligible. The pin prick and light touch tests as well as vibratory thresholds often disclosed a short period of decreased local sensibility, whereas static two-point discrimination displayed a slightly more extended postoperative sensory reduction. The patients did not experience any practical problems or essential drawbacks postoperatively. The only variable significantly associated with neurosensory disturbance was age. In conclusion, bilateral sagittal split osteotomy, when properly performed, must be considered a safe and reliable surgical technique, even from a neurosensory point of view.

Early results from reconstruction of severely atrophic (Class VI) maxillas by immediate endosseous implants in conjunction with bone grafting and Le Fort I osteotomy.

This report presents our experience with 12 consecutive patients treated by the method of SAILER19, comprising bone grafting to the floor of the nose and the maxillary sinus after a Le Fort I inferior repositioning of the maxilla followed by immediate implantation of endosseous implants. The corticocancellous grafts were harvested from the iliac crest. Fifty-nine implants were inserted in the bone grafts and eight in the adjacent nongrafted bone. Fourteen implants (21%) had to be removed because of nonintegration, of which 10 had been placed in two patients. The follow-up ranged from 11 to 24 months. No implants have been lost after loading. Six patients received fixed prostheses, and four overdentures. The importance of complete preoperative positional stability of the bone grafts and implants is emphasized.

Factors in implant integration failure after bone grafting: an osteometric and endocrinologic matched analysis.

In a retrospective analysis of 49 patients who received bone graft augmentation to the maxillary sinuses in conjunction with implant insertion, 11 patients had a significantly reduced success rate. The aim of the present study was to determine whether bone quality, as assessed by osteometry and selected haematologic and urinary tests, influences the integration of implants, and whether such data can be prognostically useful. Relative bone mass density (BMD%) differed significantly among these patients as compared to age- and sex-matched control patients receiving the same reconstructive treatment (P=0.01). Other parameters tested did not demonstrate any significant differences. In addition to local complications, general disorders, such as osteoporosis, must be considered in cases of excessive implant loss.

Importance of bone graft quality for implant integration after maxillary sinus reconstruction.

OBJECTIVE: The aim of this study was to determine whether bone quality, as assessed by osteometry and histologic parameters, can be used to predict implant integration in conjunction with maxillary sinus reconstruction. STUDY DESIGN: Twelve patients with severely atrophied maxillary alveolar processes were treated through use of a two-stage surgical reconstructive strategy with implant placement 4 months after bone grafting. Bone biopsy specimens taken from the iliac crest peroperatively and from the sinus inlay sites 1, 2, 4, 6, or 12 months postoperatively were analyzed by light microscopy and osteomorphometry. Bone mineral content was measured by osteometry. RESULTS: Osteometric and osteomorphometric data (trabecular bone volume [%], assessment of chromatin staining, and an osteocyte index) registered for the biopsy specimens were not statistically correlated with implant failure. CONCLUSIONS: Prognostic evaluation of implant survival is difficult. The tested methods did not contribute to the improvement of guidelines for the clinical handling of these patients.

A technique for inserting endosseous implants in the atrophic maxilla in a single stage procedure.

A technique is described for inserting autogenous iliac bone into the maxillary sinus of the edentulous patient via a fenestration of the anterolateral maxillary wall, maintaining the mucous membrane lining of the sinus intact, and allowing insertion of titanium screw implants into the atrophic maxilla at the same operation. This method avoids a Le Fort I osteotomy approach with its possible attendant complications.

Patients' assessment of surgical removal of mandibular third molars. An inquiry study.

The aim of this study was to find out patients' experience of pain and discomfort in connection with removal of lower third molars under local anaesthesia. Patients consecutively referred to the Oral and Maxillofacial Unit in Halmstad for removal of lower impacted third molars were the selection for this study. Three surgeons operated 294 lower third molars under local anaesthesia. The Visual Analogue Scale was used to register pain at several occasions during the surgical performance. The patients experienced the operation as an acceptable procedure and the most painful event during the operation was the injection of local anaesthetic solution. The study showed that the surgical procedure was very well tolerated by the patients with only a minor incident of inconvenience or excessive pain.