Measurement of associated production of vector bosons and top quark-antiquark pairs in pp collisions at root s=7 TeV

The first measurement of vector-boson production associated with a top quark-antiquark pair in proton-proton collisions at root s = 7 TeV is presented. The results are based on a data set corresponding to an integrated luminosity of 5.0 fb(-1), recorded by the CMS detector at the LHC in 2011. The measurement is performed in two independent channels through a trilepton analysis of t (t) over barZ events and a same-sign dilepton analysis of t (t) over barV (V = W or Z) events. In the trilepton channel a direct measurement of the t (t) over barZ cross section sigma(t (t) over barZ) = 0.28(-0.11)(+0.14) (stat)(-0.03)(+0.06) (syst) pb is obtained. In the dilepton channel a measurement of the t (t) over barV cross section yields sigma(t (t) over barV) = 0.43(-0.15)(+0.17) (stat)(-0.07)(+0.09) (syst) pb. These measurements have a significance, respectively, of 3.3 and 3.0 standard deviations from the background hypotheses and are compatible, within uncertainties, with the corresponding next-to-leading order predictions of 0.137(-0.016)(+0.012) and 0.306(-0.053)(+0.031) pb. DOI: 10.1103/PhysRevLett.110.17200

Global, regional, and national incidence and mortality burden of non-COVID-19 lower respiratory infections and aetiologies, 1990-2021: a systematic analysis from the Global Burden of Disease Study 2021

Background Lower respiratory infections (LRIs) are a major global contributor to morbidity and mortality. In 2020–21, non-pharmaceutical interventions associated with the COVID-19 pandemic reduced not only the transmission of SARS-CoV-2, but also the transmission of other LRI pathogens. Tracking LRI incidence and mortality, as well as the pathogens responsible, can guide health-system responses and funding priorities to reduce future burden. We present estimates from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 of the burden of non-COVID-19 LRIs and corresponding aetiologies from 1990 to 2021, inclusive of pandemic effects on the incidence and mortality of select respiratory viruses, globally, regionally, and for 204 countries and territories. Methods We estimated mortality, incidence, and aetiology attribution for LRI, defined by the GBD as pneumonia or bronchiolitis, not inclusive of COVID-19. We analysed 26 259 site-years of mortality data using the Cause of Death Ensemble model to estimate LRI mortality rates. We analysed all available age-specific and sex-specific data sources, including published literature identified by a systematic review, as well as household surveys, hospital admissions, health insurance claims, and LRI mortality estimates, to generate internally consistent estimates of incidence and prevalence using DisMod-MR 2.1. For aetiology estimation, we analysed multiple causes of death, vital registration, hospital discharge, microbial laboratory, and literature data using a network analysis model to produce the proportion of LRI deaths and episodes attributable to the following pathogens: Acinetobacter baumannii, Chlamydia spp, Enterobacter spp, Escherichia coli, fungi, group B streptococcus, Haemophilus influenzae, influenza viruses, Klebsiella pneumoniae, Legionella spp, Mycoplasma spp, polymicrobial infections, Pseudomonas aeruginosa, respiratory syncytial virus (RSV), Staphylococcus aureus, Streptococcus pneumoniae, and other viruses (ie, the aggregate of all viruses studied except influenza and RSV), as well as a residual category of other bacterial pathogens. Findings Globally, in 2021, we estimated 344 million (95% uncertainty interval [UI] 325–364) incident episodes of LRI, or 4350 episodes (4120–4610) per 100 000 population, and 2·18 million deaths (1·98–2·36), or 27·7 deaths (25·1–29·9) per 100 000. 502 000 deaths (406 000–611 000) were in children younger than 5 years, among which 254 000 deaths (197 000–320 000) occurred in countries with a low Socio-demographic Index. Of the 18 modelled pathogen categories in 2021, S pneumoniae was responsible for the highest proportions of LRI episodes and deaths, with an estimated 97·9 million (92·1–104·0) episodes and 505 000 deaths (454 000–555 000) globally. The pathogens responsible for the second and third highest episode counts globally were other viral aetiologies (46·4 million [43·6–49·3] episodes) and Mycoplasma spp (25·3 million [23·5–27·2]), while those responsible for the second and third highest death counts were S aureus (424 000 [380 000–459 000]) and K pneumoniae (176 000 [158 000–194 000]). From 1990 to 2019, the global all-age non-COVID-19 LRI mortality rate declined by 41·7% (35·9–46·9), from 56·5 deaths (51·3–61·9) to 32·9 deaths (29·9–35·4) per 100 000. From 2019 to 2021, during the COVID-19 pandemic and implementation of associated non-pharmaceutical interventions, we estimated a 16·0% (13·1–18·6) decline in the global all-age non-COVID-19 LRI mortality rate, largely accounted for by a 71·8% (63·8–78·9) decline in the number of influenza deaths and a 66·7% (56·6–75·3) decline in the number of RSV deaths. Interpretation Substantial progress has been made in reducing LRI mortality, but the burden remains high, especially in low-income and middle-income countries. During the COVID-19 pandemic, with its associated non-pharmaceutical interventions, global incident LRI cases and mortality attributable to influenza and RSV declined substantially. Expanding access to health-care services and vaccines, including S pneumoniae, H influenzae type B, and novel RSV vaccines, along with new low-cost interventions against S aureus, could mitigate the LRI burden and prevent transmission of LRI-causing pathogens

Adaptive laboratory evolution of Escherichia coli K-12 MG1655 for growth at high hydrostatic pressure

Much of microbial life on Earth grows and reproduces under the elevated hydrostatic pressure conditions that exist in deep-ocean and deep-subsurface environments. In this study adaptive laboratory evolution (ALE) experiments were conducted to investigate the possible modification of the piezosensitive Escherichia coli for improved growth at high pressure. After approximately 500 generations of selection, a strain was isolated that acquired the ability to grow at pressure non-permissive for the parental strain. Remarkably, this strain displayed growth properties and changes in the proportion and regulation of unsaturated fatty acids that indicated the acquisition of multiple piezotolerant properties. These changes developed concomitantly with a change in the gene encoding the acyl carrier protein, which is required for fatty acid synthesis

Bending moments of zirconia and titanium abutments with internal and external implant-abutment connections after aging and chewing simulation

Objectives: To test the fracture load of zirconia abutments with different types of implant-abutment connections after chewing simulation and to compare their bending moments to internally connected identical titanium abutments. Materials and methods: Forty-eight identical customized zirconia abutments with different implant-abutment connections were fabricated for four different test groups: one-piece internal implant-abutment connection (BL; Straumann Bonelevel), two-piece internal implant-abutment connection (RS; Nobel Biocare Replace Select), external implant-abutment connection (B; Brånemark MK III), two-piece internal implant-abutment connection (SP; Straumann Standard Plus). Twelve titanium abutments with one-piece internal implant-abutment connection (T; Straumann Bonelevel) served as control group. After aging by means of thermocycling (5-50°C, 120 s) and chewing simulation (1,200,000 cycles, 49 N load, 1.67 Hz), static load was applied at a 30° angle to the palatal surface until failure. Bending moments were calculated for comparison of the groups. Data were analyzed descriptively and by performing the Kruskal-Wallis test with Bonferroni correction. Results: The mean bending moments of the abutments were 714.1 ± 184.9 N cm (T), 331.7 ± 57.8 N cm (BL), 429.7 ± 62.8 N cm (RS), 285.8 ± 64.4 N cm (B) and 379.9 ± 59.1 N cm (SP). The bending moments of control group T were significantly higher than those of all other groups. The values of group RS were significantly higher than those of group B but within the value range of groups SP and BL. Conclusion: The bending moments of the different tested types of zirconia abutments vary with different implant-abutment connections after chewing simulation. The use of a secondary metallic component might have a beneficial influence on the stability of zirconia abutments. To cite this article: Truninger TC, Stawarczyk B, Leutert CR, Sailer TR, Hämmerle CHF, Sailer I. Bending moments of zirconia and titanium abutments with internal and external implant-abutment connections after aging and chewing simulation. Clin. Oral Impl. Res. 23, 2012; 12-18. doi: 10.1111/j.1600-0501.2010.02141.x

Bending moments of zirconia and titanium implant abutments supporting all-ceramic crowns after aging

OBJECTIVES: To test the fracture load and fracture patterns of zirconia abutments restored with all-ceramic crowns after fatigue loading, exhibiting internal and external implant-abutment connections as compared to restored and internally fixed titanium abutments. MATERIALS AND METHODS: A master abutment was used for the customization of 5 groups of zirconia abutments to a similar shape (test). The groups differed according to their implant-abutment connections: one-piece internal connection (BL; Straumann Bonelevel), two-piece internal connection (RS; Nobel Biocare ReplaceSelect), external connection (B; Branemark MkIII), two-piece internal connection (SP, Straumann StandardPlus) and one-piece internal connection (A; Astra Tech AB OsseoSpeed). Titanium abutments with internal implant-abutment connection (T; Straumann Bonelevel) served as control group. In each group, 12 abutments were fabricated, mounted to the respective implants and restored with glass-ceramic crowns. All samples were embedded in acrylic holders (ISO-Norm 14801). After aging by means of thermocycling in a chewing simulator, static load was applied until failure (ISO-Norm 14801). Fracture load was analyzed by calculating the bending moments. Values of all groups were compared with one-way ANOVA followed by Scheffé post hoc test (P-value<0.05). Failure mode was analyzed descriptively. RESULTS: The mean bending moments were 464.9 ± 106.6 N cm (BL), 581.8 ± 172.8 N cm (RS), 556.7 ± 128.4 N cm (B), 605.4 ± 54.7 N cm (SP), 216.4 ± 90.0 N cm (A) and 1042.0 ± 86.8 N cm (T). No difference of mean bending moments was found between groups BL, RS, B and SP. Test group A exhibited significantly lower mean bending moment than the other test groups. Control group T had significantly higher bending moments than all test groups. Failure due to fracture of the abutment and/or crown occurred in the test groups. In groups BL and A, fractures were located in the internal part of the connection, whereas in groups RS and SP, a partial deformation of the implant components occurred and cracks and fractures of the zirconia abutment were detected. CONCLUSION: The differently connected zirconia abutments exhibited similar bending moments with the exception of one group. Hence, the type of connection only had a minor effect on the stability of restored zirconia abutments. In general, restored titanium abutments exhibited the highest bending moments

3-Year Randomized Controlled Prospective Clinical Trial on Different CAD-CAM Implant Abutments

BACKGROUND: Zirconia abutments were introduced to restore esthetic regions and showed sufficient stability to support implant restorations. Nonetheless, to date the observation periods are shorter than those of titanium abutments. PURPOSE: To assess the survival of implant crowns supported by computer aided design-computer aided manufacturing (CAD-CAM) abutments after 3 years. MATERIALS AND METHODS: Fifty-six patients were selected for this prospective clinical study. Each patient received at least 1 titanium implant for a total of 89 fixtures. A two-stage surgical technique and no additional soft or hard tissue graft were used. The implants were randomly divided into 3 groups receiving different CAD-CAM abutments: titanium, titanium nitride, and zirconia. Zirconia or metal-ceramic crowns were used as final restorations. Cementation was the baseline and the restorations were checked after 6 months, 1, 2, and 3 years, assessing any mechanical complication. Statistical analyses were performed to evaluate the 3-year success rates. RESULTS: Five failures were reported in the zirconia group; all the failed restorations showed fractures of the abutment connection. Four failures occurred in posterior regions and one more occurred while screwing the abutment. Titanium and titanium nitride abutments had significantly higher 3-year success rates than zirconia abutments (p &lt; .05). CONCLUSIONS: Atlantis titanium and titanium nitride abutments showed optimal clinical performances after 3 years. Conversely, Atlantis zirconia abutments should be avoided to restore posterior regions