An Aminoglycoside-Sparing Regimen with Double Beta-Lactam to Successfully Treat Granulicatella adiacens Prosthetic Aortic Valve Endocarditis-Time to Change Paradigm?

(1) Background: Granulicatella adiacens is a former nutritionally variant streptococci (NVS). NVS infective endocarditis (IE) is generally characterized by a higher rate of morbidity and mortality, partially due to difficulties in choosing the most adequate microbiological culture method and the most effective treatment strategy, and partially due to higher rates of complications, such as heart failure, peripheral septic embolism, and peri-valvular abscess, as well as a higher rate of valve replacement. Depending on the affected valve (native valve endocarditisNVE, or prosthetic valve endocarditisPVE), the American Heart Association (AHA) 2015 treatment guidelines (GLs) suggest penicillin G, ampicillin, or ceftriaxone plus gentamicin (2 weeks for NVE and up to 6 weeks for PVE), while vancomycin alone may be a reasonable alternative in patients who are intolerant of β-lactam therapy. The European Society of Cardiology (ESC) 2023 GLs recommend treating NVE with penicillin G, ceftriaxone, or vancomycin for 6 weeks, suggesting combined with an aminoglycoside (AG) for at least the first 2 weeks only for PVE; likewise, the same recommendations for IE due to Enterococcus faecalis. (2) Methods: Starting from the case of a 51-year-old man with G. adiacens aortic bio-prosthesis IE who was successfully treated with aortic valve replacement combined with double beta-lactams, an AG-sparing regimen, we performed microbiology tests in order to validate this potential treatment change. (3) Results: As for E. faecalis IE, we found that the combination of ampicillin plus cephalosporines (like ceftriaxone or ceftobiprole) showed a synergistic effect in vitro, probably due to wider binding to penicillin-binding proteins (PBPs), thus contributing to enhanced bacterial killing and good clinical outcome, as well as avoiding the risk of nephrotoxicity due to AG association therapy. (4) Conclusions: Further studies are required to confirm this hypothesis, but double beta-lactams and an adequate sourcecontrol could be a choice in treating G. adiacens IE.

Heart transplantation and biomarkers: a review about their usefulness in clinical practice

Advanced heart failure (AdvHF) can only be treated definitively by heart transplantation (HTx), yet problems such right ventricle dysfunction (RVD), rejection, cardiac allograft vasculopathy (CAV), and primary graft dysfunction (PGD) are linked to a poor prognosis. As a result, numerous biomarkers have been investigated in an effort to identify and prevent certain diseases sooner. We looked at both established biomarkers, such as NT-proBNP, hs-troponins, and pro-inflammatory cytokines, and newer ones, such as extracellular vesicles (EVs), donor specific antibodies (DSA), gene expression profile (GEP), donor-derived cell free DNA (dd-cfDNA), microRNA (miRNA), and soluble suppression of tumorigenicity 2 (sST2). These biomarkers are typically linked to complications from HTX. We also highlight the relationships between each biomarker and one or more problems, as well as their applicability in routine clinical practice.

Different right ventricular dysfunction and pulmonary coupling in acute heart failure according to the left ventricular ejection fraction

BACKGROUND

Right ventricular (RV) dysfunction and pulmonary uncoupling are two acknowledged features associated with poor outcome, however few data defined RV adaptation across the different left ventricular ejection fraction (EF) cut-off. Additionally, less data are reported in patients with acute heart failure (AHF).

AIMS

The aim of present study was to analyse RV function in AHF patients presenting with either reduced or preserved EF.

METHODS

This is a multi-center observational study including 380 patients affected by AHF: 235 had AHF with reduced EF (AHFrEF) and 145 had AHF with preserved EF (AHFpEF). Pulmonary artery systolic pressure (PASP), tricuspid annular plane systolic excursion (TAPSE), S' wave velocity, and the RV end-diastolic diameter (RVEDD) were measured by echocardiography. TAPSE/PASP and S'/PASP ratios were calculated as non-invasive surrogates of RV-pulmonary arterial coupling.

RESULTS

Factors associated with poor outcome were higher values of PASP (45 [40-55] mmHg vs 40 [35-46] mmHg; p < 0.001), RVEDD (44 [38-47] mm vs 37 [35-42] mm; p < 0.001), lower TAPSE values (17 [15-20] mm vs 20 [18-22] mm; p < 0.001) and S' wave (10 [8-12] cm/s vs 11 [10-13] cm/s; p < 0.001), reduced TAPSE/PASP (0.37 [0.29-0.47] vs 0.50 [0.40-0.60]; p < 0.001) and S'/PASP ratios (0.22 [0.18-0.28] vs 0.28 [0.22-0.34]; p < 0.001). However, the prognostic parameters differed according to the LVEF value: in AHFpEF S'/PASP between 0.22 and 0.29 and > 0.29 demonstrated a protective prognostic value (Respectively HR 0.29 (0.16-0.53), p < 0.001 and HR 0.22 [0.12-0.42], p < 0.001). Conversely, in AHFrEF, TAPSE <16 mm (HR 2.59 [1.67-4.03], p < 0.001), ICV > 21 mm (HR 1.17 [1.17-1.28], p = 0.001) and TAPSE/PASP <0.49 HR 1.92 [1.10-3.37], p = 0.023) were related to adverse outcome.

CONCLUSIONS

RV adaptation and RV pulmonary coupling differ in AHF according to the level of LVEF. S' wave, and S'/PASP are associated with adverse outcome in patients with preserved EF; reduced TAPSE and TAPSE/PASP are better prognostic predictors in patients with reduced EF.

Lactococcus lactis blood products contamination resulting in fatal human case: insights from a forensic case

Lactococcus species are micro-aerophilic Gram positive bacteria characterized by low virulence features and other biotechnological properties of industrial interest. They are thus widely employed in food fermentation processes. Despite its low pathogenic potential and food grade safety, L. lactis may, however, rarely cause infections, especially among immunocompromised hosts. Moreover, the growing complexity of patients implies increased detections of such infections. This said, there is a paucity of data concerning L. lactis infections from infusion of blood transfusion products. To our knowledge, this is the first case of L. lactis infection from transfusion of blood products, as observed in an 82-year-old Caucasian male undergoing weekly platelet and blood transfusion due to sustained severe thrombocytopenia. Albeit minimally pathogenic, L. lactis should be considered for thorough testing, especially in the case of human-derived infusion products such as platelets due to their storage requirements for extended times at room temperature and their use in immunocompromised and critically ill subjects.

Cefditoren: a clinical overview

Cefditoren is an oral third-generation cephalosporin with a large spectrum activity against Gram-negative and Gram-positive bacteria which are reported to be responsible for respiratory tract and skin and skin structure infections. In this work we reviewed the pharmacodynamics, pharmacokinetics, and the main clinical indications of cefditoren. Similarly to other beta-lactams, cefditoren is a time-dependent antibiotic, and its "best" PK/PD target is probably 40% dosing interval time > 4- 5-fold MIC and 40-70% dosing interval time > 4- 5-fold MIC for bacteriostatic and bactericidal effect, respectively. In fasting patients oral bioavailability is low and increases when the drug is taken with food. This cephalosporin has significant bactericidal activity against S. pneumoniae (both penicillin-susceptible and penicillin-resistant strains), S. pyogenes, H. Influenzae and M. catarrhalis, as well as methicillin-susceptible S. aureus (MSSA). Regarding Enterobacterales, cefditoren has very low MICs90 against K. pneumoniae andE. coli but is not active against AmpC-, ESBL- and carbapenemase-producer' strains. Licensed indications are treatment of exacerbations of chronic bronchitis,acute rhinosinusitis, otitis media, upper respiratory tract infections (pharyngitis/tonsillitis), lower community-acquired respiratory tract infections (LRTIs), and skin and skin-structure infections (SSTI). Cefditoren might have a role in switching from parenteral to oral therapy in acute pyelonephritis and LRTIs. with a reduction of adverse effects and hospital costs. Eventually, due to its supposed binding to enterococcal penicillin binding proteins (PBPs) cefditoren, in combination with other beta-lactams, might have a role in partial oral enterococcal endocarditis treatment..

Analysis of the risk of a secondary displacement in conservati- vely treated paediatric distal radius metaphyseal fractures. A multicentric study

OBJECTIVES

Distal radius fractures represent one of the most fre-quent injuries in children. The treatment of choice is a closed reduction followed by immobilisation in plaster cast; the immediate recourse to osteosynthesis with Kirschner wires is only reserved for certain cases. The displacement rate reported in the literature is 21-39%. The aim of this study is to retrospectively evaluate the risk factors for a secondary displacement of metaphyseal radius fractures in a paediatric population treated in three different centres.

MATERIALS AND METHODS

The initial treatment for all 360 patients examined was a closed reduction under general anaesthesia and im-mobilisation in an above elbow cast for 4 weeks. The pre-operative displacement, residual post-reduction displacement and possible di-splacement at 7 and 14 days of follow-up were all assessed clinically and radiographically.

RESULTS

A loss of reduction was reported in 102 cases; 51 under-went an additional reduction procedure - some followed by osteo-synthesis - while in the remaining 51 cases, the loss of reduction was acceptable in relation to the expectation of remodelling. The most statistically significant variable for the occurrence of a secondary displacement is a severe primary displacement. The association with the ulna fracture is not significantly correlated. The quality of the plaster cast is important for maintaining the reduction. There are a few things to consider as indicators for a second procedure: age, time elapsed from moment of fracture, fracture site and the absence of an acceptable reduction.

CONCLUSIONS

In our experience, a reduction followed by osteo-synthesis with Kirschner wires should be considered the treatment of choice in fractures with a high risk of secondary displacement, namely those with severe initial displacement or unsatisfactory reduction.

Prospects on the Potential In Vitro Regenerative Features of Mechanically Treated-Adipose Tissue for Osteoarthritis Care

Gathering a better grasp on the adipose stromal vascular fraction (SVF) is demanding among clinicians for osteoarthritis (OA) care because of its promising but multifaceted clinical outcomes. The aim of this preclinical in vitro study was to test whether the mechanical approach with Hy-Tissue SVF system, a class IIa CE marked device of adipose tissue micro-fragmentation, influences the biological features and functions of SVF. We compared mechanical generated-SVF (mSVF) with the enzymatic generated-SVF (eSVF) by testing cell survival, phenotype, differentiation, and paracrine properties using ELISA assays. Both adipose SVF showed 80% viable cells and enrichment for CD-44 marker. The mSVF product preserved the functions of cell populations within the adipose tissue; however, it displayed lowered nucleated cell recovery and CFU-F than eSVF. As for multipotency, mSVF and eSVF showed similar differentiation commitment for osteochondral lineages. Both adipose SVF exhibited an increased release of VEGF, HGF, IGF-1 and PDGF-bb, involved in pathways mediating osteochondral repair and cell migration. Both mSVF and eSVF also displayed high release for the anti-inflammatory cytokine IL-10. After in vitro culture, supernatants from both mSVF and eSVF groups showed a low release of cytokines except for IL-10, thereby giving evidence of functional changes after culture expansion. In this study, mSVF showed active cell populations in the adipose tissue comparable to eSVF with excellent survival, differentiation and paracrine properties under a new mechanical adipose tissue micro-fragmentation system; thereby suggesting its potential use as a minimally invasive technique for OA treatment.

Spinal fusion procedures in the adult and young population: a systematic review on allogenic bone and synthetic grafts when compared to autologous bone

This systematic review aims to compare clinical evidences related to autologous iliac crest bone graft (ICBG) and non-ICBG (local bone) with allografts and synthetic grafts for spinal fusion procedures in adult and young patients. A systematic search was carried out in three databases (PubMed, Scopus, Web of Science, Cochrane Central Register of Controlled Trials) to identify clinical studies in the last 10 years. The initial search retrieved 1085 studies, of which 24 were recognized eligible for the review. Twelve studies (4 RCTs, 5 prospective, 3 retrospective) were focused on lumbar spine, 9 (2 RCTs, 2 prospective, 4 retrospective, 1 case-series) on cervical spine and 3 (1 RCT, 2 retrospective) on spinal fusion procedures in young patients. Calcium phosphate ceramics, allografts, bioglasses, composites and polymers have been clinically investigated as substitutes of autologous bone in spinal fusion procedures. Of the 24 studies included in this review, only 1 RCT on cervical spine was classified with high level of evidence (Class I) and showed low risk of bias. This RCT demonstrated the safety and efficacy of the proposed treatment, a composite bone substitute, that results in similar and on some metrics superior outcomes compared with local autograft bone. Almost all other studies showed moderately or, more often, high incidence of bias (Class III), thus preventing ultimate conclusion on the hypothesized beneficial effects of allografts and synthetic grafts. This review suggests that users of allografts and synthetic grafting should carefully consider the scientific evidence concerning efficacy and safety of these bone substitutes, in order to select the best option for patient undergoing spinal fusion procedures.

A solution based on melatonin, tryptophan, and vitamin B6 (Melamil Tripto©) for sedation in newborns during brain MRI

INTRODUCTION

Melatonin has been studied and used for several years as a sleep-wake cycle modulator in patients with sleep disorders. Experimental evidence has demonstrated the multiple neuroprotective benefits of this indoleamine secreted by the pineal gland. Melatonin is also used in neurological investigations, for its ability to induce sleep in children. In fact, it favors falling asleep during electroencephalogram, Magnetic Resonance Imaging (MRI), and during brainstem auditory evoked potentials. Previous studies are focused on infants and children. No investigation have been performed in neonates, before or during instrumental assessments.

MATERIAL AND METHODS

One hundred ten newborns (term and preterm) undergoing brain MRI were enrolled in the study. Thirty minutes before the planned time for the examination, we administered a single dose solution of melatonin- tryptophan-vitamin B6. Twenty minutes after the initial administration of 2 mg, a second dose of 1 mg was administered, if the baby was still awake. If after further 15 min the baby was still not sleeping, an additional dose of 1 mg was administered.

RESULTS

In 106 patients we obtained adequate sedation without adverse events, allowing us to perform an adequate quality MRI, with a median time of 25 min to reach sleeping. Only in three patients MRI could not be performed. In patients having a large weight, higher doses of melatonin were necessary to reach sleeping. Considering the pro kg dose of melatonin, the average dose that induced sleepiness in neonates was 0,64 ± 0.16 mg/Kg.

CONCLUSION

A solution based on Melatonin- tryptophan-vitamin B6 can be a helpful sedative to administer to neonates undergoing brain MRI, avoiding the use of anesthetics and achieving adequate assessments.

Prevalence of Catatonia and Its Moderators in Clinical Samples: Results from a Meta-analysis and Meta-regression Analysis

Catatonia is an independent syndrome that co-occurs with several mental and medical conditions. We performed a systematic literature review in PubMed/Scopus until February 2017 and meta-analyzed studies reporting catatonia prevalence. Across 74 studies (cross-sectional = 32, longitudinal = 26, retrospective = 16) providing data collected from 1935 to 2017 across all continents, mean catatonia prevalence was 9.0% (k = 80, n = 110764; 95% CI = 6.9-11.7, I2 = 98%, publication bias P < .01), decreasing to 7.8% (k = 19, n = 7612, 95% CI = 7-8.7, I2 = 38.9%) in a subgroup with low heterogeneity. Catatonia prevalence was 23.9% (k = 8, n = 1168, 95% CI = 10-46.9, I2 = 96%) in patients undergoing ECT/having elevated creatinine phosphokinase. Excluding ECT samples, the catatonia prevalence was 8.1% (k = 72, n = 109606, 95% CI = 6.1-10.5, I2 = 98%, publication bias P < .01), with sensitivity analyses demonstrating that country of study origin (P < .001), treatment setting (P = .003), main underlying condition (P < .001), and sample size (P < .001)moderated catatonia prevalence, being highest in Uganda (48.5%, k = 1) and lowest in Mexico (1.9%, 95% CI = 0.4-8.8, I2 = 67%, k = 2), highest in nonpsychiatric out- or inpatient services (15.8%, 95% CI = 8.1-28.4, I2 = 97%, k = 15)and lowest in psychiatric outpatients services (3.2%, 95% CI = 1.7-6.1, I2 = 50%, k = 3), highest in presence of medical or neurological illness with no comorbid psychiatric condition (20.6%, 95% CI = 11.5-34.2, I2 = 95%, k = 10)and lowest in mixed psychiatric samples (5.7%, 95% CI = 4.2-7.7, I2 =98%, k = 43), highest in studies with sample sizes <100 (20.7%, 95% CI = 12.8-31.6, I2 = 90%, k = 17) and lowest in studies with sample sizes >1000 (2.3%, 95% CI = 1.3-3.9, I2 = 99%, k = 16). Meta-regression showed that smaller sample size (P < .01) and less major depressive disorder (P = .02) moderated higher catatonia prevalence. Year of data collection did not significantly moderate the results. Results from this first meta-analysis of catatonia frequencies across time and disorders suggest that catatonia is an epidemiologically and clinically relevant condition that occurs throughout several mental and medical conditions, whose prevalence has not decreased over time and does not seem to depend on different rating scales/criteria. However, results were highly heterogeneous, calling for a cautious interpretation.

Measurement of b hadron lifetimes in pp collisions at s = 8 TeV

Measurements are presented of the lifetimes of theB 0 ,B s 0 , Λ b 0 , and B c + hadrons using the decay channelsB 0 → J / ψ K ∗ ( 892 ) 0 ,B 0 → J / ψ K S 0 ,B s 0 → J / ψ π + π - ,B s 0 → J / ψ ϕ ( 1020 ) ,Λ b 0 → J / ψ Λ 0 , andB c + → J / ψ π + . The data sample, corresponding to an integrated luminosity of 19.7fb -1 , was collected by the CMS detector at the LHC in proton-proton collisions ats = 8 TeV . TheB 0 lifetime is measured to be 453.0 ± 1.6 (stat) ± 1.8 (syst) μ m in J / ψ K ∗ ( 892 ) 0 and 457.8 ± 2.7 (stat) ± 2.8 (syst) μ m in J / ψ K S 0 , which results in a combined measurement of c τ B 0 = 454.1 ± 1.4 (stat) ± 1.7 (syst) μ m . The effective lifetime of theB s 0 meson is measured in two decay modes, with contributions from different amounts of the heavy and light eigenstates. This results in two different measured lifetimes: c τ B s 0 → J / ψ π + π - = 502.7 ± 10.2 (stat) ± 3.4 (syst) μ m and c τ B s 0 → J / ψ ϕ ( 1020 ) = 443.9 ± 2.0 (stat) ± 1.5 (syst) μ m . The Λ b 0 lifetime is found to be 442.9 ± 8.2 (stat) ± 2.8 (syst) μ m . The precision from each of these channels is as good as or better than previous measurements. The B c + lifetime, measured with respect to theB + to reduce the systematic uncertainty, is 162.3 ± 7.8 (stat) ± 4.2 (syst) ± 0.1 ( τ B + ) μ m . All results are in agreement with current world-average values.

Measurement of Prompt D^{0} Meson Azimuthal Anisotropy in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

The prompt D^{0} meson azimuthal anisotropy coefficients, v_{2} and v_{3}, are measured at midrapidity (|y|<1.0) in Pb-Pb collisions at a center-of-mass energy sqrt[s_{NN}]=5.02  TeV per nucleon pair with data collected by the CMS experiment. The measurement is performed in the transverse momentum (p_{T}) range of 1 to 40  GeV/c, for central and midcentral collisions. The v_{2} coefficient is found to be positive throughout the p_{T} range studied. The first measurement of the prompt D^{0} meson v_{3} coefficient is performed, and values up to 0.07 are observed for p_{T} around 4  GeV/c. Compared to measurements of charged particles, a similar p_{T} dependence, but smaller magnitude for p_{T}<6  GeV/c, is found for prompt D^{0} meson v_{2} and v_{3} coefficients. The results are consistent with the presence of collective motion of charm quarks at low p_{T} and a path length dependence of charm quark energy loss at high p_{T}, thereby providing new constraints on the theoretical description of the interactions between charm quarks and the quark-gluon plasma.

First Recurrence Analysis of 840 Cutaneous Melanomas: A Proposal for a Follow-Up Schedule

Aims and background

A correct follow-up schedule for patients who underwent an excision for stage I cutaneous melanoma might allow the early detection of local and distant metastases. At present, there is no general agreement on follow-up protocols. In order to work out a follow-up guide, we have retrospectively evaluated the records of 840 stage I cutaneous melanoma patients surgically treated and followed during the postoperative period in the Division of Plastic Surgery of the University of Florence from 1975 to 1992.

Methods

We evaluated the patients’ records by analyzing time, pathway and site of any first recurrence in relation to the main prognostic factors such as patient sex, site, histological type and depth of invasion of each primary melanoma. A statistical analysis was performed.

Results

To summarize, the salient results were the following: 80% of relapses occurred in the first 3 years and they occurred significantly earlier when the primary melanoma was localized in the trunk and significantly later when the melanoma was localized in the lower limbs and for < 1.5 mm lesions. The first recurrence occurred earlier by the lymphatic than by the hematic pathway regarding the overall number of patients. The hematic pathway was the most frequent (with respect to the overall percentage of hematic metastases) for the melanomas localized in the head and neck region and for lentigo malignant melanomas, whereas the lymphatic pathway was most frequent for melanomas of the lower limbs and > 3 mm in thickness.

Conclusions

We suggest a follow-up schedule taking into consideration the postoperative behavior of stage I cutaneous melanoma patients (in terms of time and pathway of the first recurrence) in relation to the site and depth of invasion of the tumor.

Measurement of associated Z + charm production in proton-proton collisions at s = 8 TeV

A study of the associated production of a Z boson and a charm quark jet ( Z + c ), and a comparison to production with a b quark jet ( Z + b ), in p p collisions at a centre-of-mass energy of 8TeV are presented. The analysis uses a data sample corresponding to an integrated luminosity of 19.7fb - 1 , collected with the CMS detector at the CERN LHC. The Z boson candidates are identified through their decays into pairs of electrons or muons. Jets originating from heavy flavour quarks are identified using semileptonic decays of c or b flavoured hadrons and hadronic decays of charm hadrons. The measurements are performed in the kinematic region with two leptons withp T ℓ > 20 GeV ,| η ℓ | < 2.1 , 71 < m ℓ ℓ < 111 GeV , and heavy flavour jets withp T jet > 25 GeV and| η jet | < 2.5 . The Z + c production cross section is measured to be σ ( p p → Z + c + X ) B ( Z → ℓ + ℓ - ) = 8.8 ± 0.5 (stat) ± 0.6 (syst) pb . The ratio of the Z + c and Z + b production cross sections is measured to be σ ( p p → Z + c + X ) / σ ( p p → Z + b + X ) = 2.0 ± 0.2 (stat) ± 0.2 (syst) . The Z + c production cross section and the cross section ratio are also measured as a function of the transverse momentum of the Z boson and of the heavy flavour jet. The measurements are compared with theoretical predictions.

Measurement of the Splitting Function in pp and Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

Data from heavy ion collisions suggest that the evolution of a parton shower is modified by interactions with the color charges in the dense partonic medium created in these collisions, but it is not known where in the shower evolution the modifications occur. The momentum ratio of the two leading partons, resolved as subjets, provides information about the parton shower evolution. This substructure observable, known as the splitting function, reflects the process of a parton splitting into two other partons and has been measured for jets with transverse momentum between 140 and 500 GeV, in pp and PbPb collisions at a center-of-mass energy of 5.02 TeV per nucleon pair. In central PbPb collisions, the splitting function indicates a more unbalanced momentum ratio, compared to peripheral PbPb and pp collisions.. The measurements are compared to various predictions from event generators and analytical calculations.

Suppression of Excited ϒ States Relative to the Ground State in Pb-Pb Collisions at sqrt[s]_{NN}=5.02 TeV

The relative yields of ϒ mesons produced in pp and Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV and reconstructed via the dimuon decay channel are measured using data collected by the CMS experiment. Double ratios are formed by comparing the yields of the excited states, ϒ(2S) and ϒ(3S), to the ground state, ϒ(1S), in both Pb-Pb and pp collisions at the same center-of-mass energy. The double ratios, [ϒ(nS)/ϒ(1S)]_{Pb-Pb}/[ϒ(nS)/ϒ(1S)]_{pp}, are measured to be 0.308±0.055(stat)±0.019(syst) for the ϒ(2S) and less than 0.26 at 95% confidence level for the ϒ(3S). No significant ϒ(3S) signal is found in the Pb-Pb data. The double ratios are studied as a function of collision centrality, as well as ϒ transverse momentum and rapidity. No significant dependencies are observed.

Study of dijet events with a large rapidity gap between the two leading jets in pp collisions at s = 7 TeV

Events with no charged particles produced between the two leading jets are studied in proton-proton collisions ats = 7 TeV . The jets were required to have transverse momentump T jet > 40 GeV and pseudorapidity1.5 < | η jet | < 4.7 , and to have values of η jet with opposite signs. The data used for this study were collected with the CMS detector during low-luminosity running at the LHC, and correspond to an integrated luminosity of 8pb - 1 . Events with no charged particles withp T > 0.2 GeV in the interval - 1 < η < 1 between the jets are observed in excess of calculations that assume no color-singlet exchange. The fraction of events with such a rapidity gap, amounting to 0.5-1% of the selected dijet sample, is measured as a function of the p T of the second-leading jet and of the rapidity separation between the jets. The data are compared to previous measurements at the Tevatron, and to perturbative quantum chromodynamics calculations based on the Balitsky-Fadin-Kuraev-Lipatov evolution equations, including different models of the non-perturbative gap survival probability.

The Ovariectomized Ewe Model in the Evaluation of Biomaterials for Prosthetic Devices in Spinal Fixation

The effect of surgical ovariectomy on cancellous bone was investigated by comparing mechanical properties and microarchitectural characteristics of the lumbar vertebrae in ovariectomized and sham-operated ewes. Eighteen mongrel ewes, 4±1 years old, were randomly divided into three groups: 6 animals served as a control group (Baseline), 6 were bilaterally ovariectomized (OVX), and the others were used as a sham-operated group (SHAM). OVX and SHAM ewes were euthanized 24 months after surgery; the L5 vertebrae were processed for mechanical and histomorphometric analyses. Maximum load, maximum strength (p<0.0005) and elastic modulus (p <0.005) decreased by about 28% in the OVX group in comparison with the other groups. In the OVX group, vertebral cancellous bone volume, trabecular thickness and trabecular number decreased by about 32% (p<0.0005), 15% (p=0.001) and 20% (p=0.019), respectively. An overall decrease in the bone turnover rate of the OVX group was registered in terms of bone formation rate (p= 0.007) and activation frequency (p<0.0005). The variations observed in cancellous bone mechanics and histomorphometry would suggest the development of an osteopenic state in ewe vertebrae at 24 months. Such findings may be useful for future experimental investigations on biomaterials and prosthetic devices to be implanted in the osteopenic spine.

A Resorbable Biomaterial Shaped as a Tubular Chamber and Containing Stem Cells: A Pilot Study on Artificial Bone Regeneration

In a previous study, we showed how healing of non-union defects in rabbit radii can be achieved by means of a tubular resorbable chamber, in comparison with untreated defects. In the present study, we placed bone marrow stem cells inside the chamber. Bone marrow was obtained by percutaneous aspiration from the iliac crest in 9 adult New Zealand rabbits. Stem cells were separated by the centrifugation technique. In the same animals, a defect of 10 mm was created in both radii. On the left side, the defect was treated with the poly-DL-Lactide chamber, in which a suspension of autologous cells was injected; on the right side, only autologous cells were used. Radiological and histomorphometric data were compared within this study as well as with the results of our previous study. At 3, 6 and 9 months, there was no healing on the right side. On the left side, progressive bone formation with reunion of the stumps was observed in the chamber. We conclude that stem cells can accelerate bone healing when contained in the tubular chamber.

The Ovariectomised Sheep as a Model for Testing Biomaterials and Prosthetic Devices in Osteopenic Bone: A Preliminary Study on Iliac Crest Biopsies

A histomorphometric and ultrastructural evaluation on sheep iliac bone was performed. Six sheep were ovariectomised (OVX Group) and 6 were left intact (Sham-aged, Control Group). An iliac crest biopsy was performed randomly in 6 animals at the beginning of the study, then, in all the animals, after 12 and 24 months. A significant decrease in trabecular bone volume, trabecular thickness (p<0.0005) and cell volume (p<0.005) was observed in OVX animals. A modest decrease in trabecular number and osteoid thickness together with an increase in trabecular separation were observed in OVX animals at 12 and 24 months. The osteoid volume showed a significant difference (p<0.05) between the groups. In OVX animals, at 12 months, Scanning Electron Microscopy revealed an enlargement of the trabecular space and a progressive replacement of bone matrix with adipose tissue. These signs were accentuated at 24 months.

In conclusion, OVX sheep showed a loss of trabecular bone starting at 12 months after ovariectomy. The developed osteopenic state may be considered as a useful tool when doing research on biomaterial osteointegration. (Int J Artif Organs 2000; 23: 275–81)

Estrogen, Progesterone Receptors and Proliferating Activity Evaluated by Immunocytochemistry in Breast Cancer

The correlation of the most important prognostic indicators was evaluated in 75 breast cancer cases. Estrogen-progesterone receptors and proliferating activity were analyzed by immunocytochemical methods (ER-ICA, PR-ICA, Ki-67). Both steroid receptors were inversely correlated with the proliferating activity (ER-ICA vs Ki-67, p < 0.003; PR-ICA vs. Ki-67, p < 0.0001). No correlation was found between steroid receptors or cell kinetics and tumor size or lymph node status. These findings confirm the relevance of biochemical and kinetic parameters as independent markers in breast cancer and suggest a routine use of the simple immunocytochemical methods in assessing the biological behavior of tumors.

Observation of Correlated Azimuthal Anisotropy Fourier Harmonics in pp and p+Pb Collisions at the LHC

The azimuthal anisotropy Fourier coefficients (v_{n}) in 8.16 TeV p+Pb data are extracted via long-range two-particle correlations as a function of the event multiplicity and compared to corresponding results in pp and PbPb collisions. Using a four-particle cumulant technique, v_{n} correlations are measured for the first time in pp and p+Pb collisions. The v_{2} and v_{4} coefficients are found to be positively correlated in all collision systems. For high-multiplicity p+Pb collisions, an anticorrelation of v_{2} and v_{3} is observed, with a similar correlation strength as in PbPb data at the same multiplicity. The new correlation results strengthen the case for a common origin of the collectivity seen in p+Pb and PbPb collisions in the measured multiplicity range.

Measurements of the p p → Z Z production cross section and the Z → 4 ℓ branching fraction, and constraints on anomalous triple gauge couplings at s = 13 TeV

Four-lepton production in proton-proton collisions, p p → ( Z / γ ∗ ) ( Z / γ ∗ ) → 4 ℓ , where ℓ = e or μ , is studied at a center-of-mass energy of 13TeV with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 35.9fb - 1 . The ZZ production cross section, σ ( p p → Z Z ) = 17.2 ± 0.5 (stat) ± 0.7 (syst) ± 0.4 (theo) ± 0.4 (lumi) pb , measured using events with two opposite-sign, same-flavor lepton pairs produced in the mass region 60 < m ℓ + ℓ - < 120 GeV , is consistent with standard model predictions. Differential cross sections are measured and are well described by the theoretical predictions. The Z boson branching fraction to four leptons is measured to be B ( Z → 4 ℓ ) = 4 . 83 - 0.22 + 0.23 ( s t a t ) - 0.29 + 0.32 ( s y s t ) ± 0.08 ( t h e o ) ± 0.12 ( l u m i ) × 10 - 6 for events with a four-lepton invariant mass in the range 80 < m 4 ℓ < 100 GeV and a dilepton massm ℓ ℓ > 4 GeV for all opposite-sign, same-flavor lepton pairs. The results agree with standard model predictions. The invariant mass distribution of the four-lepton system is used to set limits on anomalous ZZZ and ZZ γ couplings at 95% confidence level: - 0.0012 < f 4 Z < 0.0010 , - 0.0010 < f 5 Z < 0.0013 , - 0.0012 < f 4 γ < 0.0013 , - 0.0012 < f 5 γ < 0.0013 .

Measurements of the p p → Z Z production cross section and the Z → 4 ℓ branching fraction, and constraints on anomalous triple gauge couplings at s = 13 TeV

Four-lepton production in proton-proton collisions, p p → ( Z / γ ∗ ) ( Z / γ ∗ ) → 4 ℓ , where ℓ = e or μ , is studied at a center-of-mass energy of 13 TeV with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 35.9 fb - 1 . The ZZ production cross section, σ ( p p → Z Z ) = 17.2 ± 0.5 (stat) ± 0.7 (syst) ± 0.4 (theo) ± 0.4 (lumi) pb , measured using events with two opposite-sign, same-flavor lepton pairs produced in the mass region 60 < m ℓ + ℓ - < 120 GeV , is consistent with standard model predictions. Differential cross sections are measured and are well described by the theoretical predictions. The Z boson branching fraction to four leptons is measured to be B ( Z → 4 ℓ ) = 4 . 83 - 0.22 + 0.23 ( s t a t ) - 0.29 + 0.32 ( s y s t ) ± 0.08 ( t h e o ) ± 0.12 ( l u m i ) × 10 - 6 for events with a four-lepton invariant mass in the range 80 < m 4 ℓ < 100 GeV and a dilepton mass m ℓ ℓ > 4 GeV for all opposite-sign, same-flavor lepton pairs. The results agree with standard model predictions. The invariant mass distribution of the four-lepton system is used to set limits on anomalous ZZZ and ZZ γ couplings at 95% confidence level: - 0.0012 < f 4 Z < 0.0010 , - 0.0010 < f 5 Z < 0.0013 , - 0.0012 < f 4 γ < 0.0013 , - 0.0012 < f 5 γ < 0.0013 .

Osseointegration of Sandblasted or Anodised Hydrothermally-Treated Titanium Implants: Mechanical, Histomorphometric and Bone Hardness Measurements

The improvement of the implant-bone interface is still an open problem in the long-term mechanical stability of cementless fixed implants. Mechanical, histomorphometric and bone hardness measurements were performed in sheep femoral cortical bone implants at 8 and 12 weeks from surgery to compare in vivo the osseointegration of titanium screws (Ø 3.5 mm × 7 mm length) with two different surface treatments: sandblasting with 70–100 μm HA followed by acid etching with HNO3 (Group A) and Ca-P anodization followed by a hydrothermal treatment (Group B). No significant differences were found for maximum push-out force and interfacial strength between groups at both experimental times. No significant difference was observed for Bone Ingrowth between groups at both experimental times, while the Affinity Index of Group B was significantly higher (7.5%, p<0.05) and lower (10.2%, p<0.05) than that of Group A at 8 and 12 weeks, respectively. Finally, a significant increase in bone microhardness measured within 200 μm from the interface and inside the thread depth of Group A was observed between the two experimental times (p<0.05). In conclusion, present findings show that osseointegration may be accelerated by adequate surface roughness and bioactive ceramic coating such as current tested treatments which enhance bone interlocking and mineralization.

Shock Wave Therapy as an Innovative Technology in Skeletal Disorders: Study on Transmembrane Current in Stimulated Osteoblast-Like Cells

Extracorporeal shock wave treatment (ESWT) is successfully used in various musculoskeletal disorders and pathologies. Despite the increasing use of this kind of therapy, some aspects of its mechanism of action are still unclear. In vitro bone cell behavior under ESWT were previously investigated by the present author and MG63 osteoblast-like cells showed an enhancement in proliferation and in the osteoblast differentiation after therapy with a low-energy flux density. The aim of the present study was to evaluate the effect of ESWT on the permeabilization of cell membrane. We characterized physiological changes in the MG63 associated with ESWT generated by an ESW device and patch clamp recording was performed to study ion channels. Experiments were carried out using the whole-cell recording configuration of the patch-clamp technique and the ionic current measurements were performed on cell samples of ESW treated and control groups. The patch-clamp technique showed the effect of ESWT on the amplitude of transmembrane currents. The treatment with ESW enhanced the transmembrane current as well the voltage dependence of Ca-activated and K channels that mediate these currents: the differences between treated cells and control at 80mV were over 1000 pA (P<0.05). These modifications of ion channels activity positively influence cell proliferation (MTT test, P<0.0001) without interfering with the normal synthesis activity of stimulated osteoblasts.

Search for dark matter produced in association with heavy-flavor quark pairs in proton-proton collisions at s = 13 TeV

A search is presented for an excess of events with heavy-flavor quark pairs ( t t ¯ and b b ¯ ) and a large imbalance in transverse momentum in data from proton-proton collisions at a center-of-mass energy of 13TeV . The data correspond to an integrated luminosity of 2.2fb - 1 collected with the CMS detector at the CERN LHC. No deviations are observed with respect to standard model predictions. The results are used in the first interpretation of dark matter production in t t ¯ and b b ¯ final states in a simplified model. This analysis is also the first to perform a statistical combination of searches for dark matter produced with different heavy-flavor final states. The combination provides exclusions that are stronger than those achieved with individual heavy-flavor final states.

Search for Evidence of the Type-III Seesaw Mechanism in Multilepton Final States in Proton-Proton Collisions at sqrt[s]=13 TeV

A search for a signal consistent with the type-III seesaw mechanism in events with three or more electrons or muons is presented. The data sample consists of proton-proton collisions at sqrt[s]=13  TeV collected by the CMS experiment at the LHC in 2016 and corresponds to an integrated luminosity of 35.9  fb^{-1}. Selection criteria based on the number of leptons and the invariant mass of oppositely charged lepton pairs are used to distinguish the signal from the standard model background. The observations are consistent with the expectations from standard model processes. The results are used to place limits on the production of heavy fermions of the type-III seesaw model as a function of the branching ratio to each lepton flavor. In the scenario of equal branching fractions to each lepton flavor, heavy fermions with masses below 840 GeV are excluded. This is the most sensitive probe to date of the type-III seesaw mechanism.

Measurements of the associated production of a Z boson and b jets in pp collisions at s = 8 TeV

Measurements of the associated production of a Z boson with at least one jet originating from a b quark in proton-proton collisions ats = 8 TeV are presented. Differential cross sections are measured with data collected by the CMS experiment corresponding to an integrated luminosity of 19.8fb - 1 . Z bosons are reconstructed through their decays to electrons and muons. Cross sections are measured as a function of observables characterizing the kinematics of the b jet and the Z boson. Ratios of differential cross sections for the associated production with at least one b jet to the associated production with any jet are also presented. The production of a Z boson with at least two b jets is investigated, and differential cross sections are measured for the dijet system. Results are compared to theoretical predictions, testing two different flavour schemes for the choice of initial-state partons.

Measurement of the triple-differential dijet cross section in proton-proton collisions at s = 8 TeV and constraints on parton distribution functions

A measurement is presented of the triple-differential dijet cross section at a centre-of-mass energy of 8TeV using 19.7fb -1 of data collected with the CMS detector in proton-proton collisions at the LHC. The cross section is measured as a function of the average transverse momentum, half the rapidity separation, and the boost of the two leading jets in the event. The cross section is corrected for detector effects and compared to calculations in perturbative quantum chromodynamics at next-to-leading order accuracy, complemented with electroweak and nonperturbative corrections. New constraints on parton distribution functions are obtained and the inferred value of the strong coupling constant isα S ( M Z ) = 0.1199 ± 0.0015 ( exp ) - 0.0020 + 0.0031 ( theo ) , where M Z is the mass of the Z boson.

Search for new phenomena with the M T 2 variable in the all-hadronic final state produced in proton-proton collisions at s = 13 TeV

A search for new phenomena is performed using events with jets and significant transverse momentum imbalance, as inferred through the M T 2 variable. The results are based on a sample of proton-proton collisions collected in 2016 at a center-of-mass energy of 13TeV with the CMS detector and corresponding to an integrated luminosity of 35.9fb -1 . No excess event yield is observed above the predicted standard model background, and the results are interpreted as exclusion limits at 95% confidence level on the masses of predicted particles in a variety of simplified models of R-parity conserving supersymmetry. Depending on the details of the model, 95% confidence level lower limits on the gluino (light-flavor squark) masses are placed up to 2025 (1550)GeV . Mass limits as high as 1070 (1175)GeV are set on the masses of top (bottom) squarks. Information is provided to enable re-interpretation of these results, including model-independent limits on the number of non-standard model events for a set of simplified, inclusive search regions.

Measurement of the B^{±} Meson Nuclear Modification Factor in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

The differential production cross sections of B^{±} mesons are measured via the exclusive decay channels B^{±}→J/ψK^{±}→μ^{+}μ^{-}K^{±} as a function of transverse momentum in pp and Pb-Pb collisions at a center-of-mass energy sqrt[s_{NN}]=5.02  TeV per nucleon pair with the CMS detector at the LHC. The pp(Pb-Pb) data set used for this analysis corresponds to an integrated luminosity of 28.0  pb^{-1} (351  μb^{-1}). The measurement is performed in the B^{±} meson transverse momentum range of 7 to 50  GeV/c, in the rapidity interval |y|<2.4. In this kinematic range, a strong suppression of the production cross section by about a factor of 2 is observed in the Pb-Pb system in comparison to the expectation from pp reference data. These results are found to be roughly compatible with theoretical calculations incorporating beauty quark diffusion and energy loss in a quark-gluon plasma.

Search for Supersymmetry in pp Collisions at sqrt[s]=13 TeV in the Single-Lepton Final State Using the Sum of Masses of Large-Radius Jets

Results are reported from a search for supersymmetric particles in proton-proton collisions in the final state with a single lepton, multiple jets, including at least one b-tagged jet, and large missing transverse momentum. The search uses a sample of proton-proton collision data at sqrt[s]=13  TeV recorded by the CMS experiment at the LHC, corresponding to an integrated luminosity of 35.9  fb^{-1}. The observed event yields in the signal regions are consistent with those expected from standard model backgrounds. The results are interpreted in the context of simplified models of supersymmetry involving gluino pair production, with gluino decay into either on- or off-mass-shell top squarks. Assuming that the top squarks decay into a top quark plus a stable, weakly interacting neutralino, scenarios with gluino masses up to about 1.9 TeV are excluded at 95% confidence level for neutralino masses up to about 1 TeV.

Search for Charged Higgs Bosons Produced via Vector Boson Fusion and Decaying into a Pair of W and Z Bosons Using pp Collisions at sqrt[s]=13 TeV

A search for charged Higgs bosons produced via vector boson fusion and decaying into W and Z bosons using proton-proton collisions at sqrt[s]=13  TeV is presented. The data sample corresponds to an integrated luminosity of 15.2  fb^{-1} collected with the CMS detector in 2015 and 2016. The event selection requires three leptons (electrons or muons), two jets with large pseudorapidity separation and high dijet mass, and missing transverse momentum. The observation agrees with the standard model prediction. Limits on the vector boson fusion production cross section times branching fraction for new charged physical states are reported as a function of mass from 200 to 2000 GeV and interpreted in the context of Higgs triplet models.

Search for heavy resonances that decay into a vector boson and a Higgs boson in hadronic final states at s = 13 TeV

A search for heavy resonances with masses above 1TeV , decaying to final states containing a vector boson and a Higgs boson, is presented. The search considers hadronic decays of the vector boson, and Higgs boson decays to b quarks. The decay products are highly boosted, and each collimated pair of quarks is reconstructed as a single, massive jet. The analysis is performed using a data sample collected in 2016 by the CMS experiment at the LHC in proton-proton collisions at a center-of-mass energy of 13TeV , corresponding to an integrated luminosity of 35.9fb - 1 . The data are consistent with the background expectation and are used to place limits on the parameters of a theoretical model with a heavy vector triplet. In the benchmark scenario with mass-degenerate W ' andZ ' bosons decaying predominantly to pairs of standard model bosons, for the first time heavy resonances for masses as high as 3.3TeV are excluded at 95% confidence level, setting the most stringent constraints to date on such states decaying into a vector boson and a Higgs boson.

Search for Low Mass Vector Resonances Decaying to Quark-Antiquark Pairs in Proton-Proton Collisions at sqrt[s]=13 TeV

A search is reported for a narrow vector resonance decaying to quark-antiquark pairs in proton-proton collisions at sqrt[s]=13  TeV, collected with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 2.7   fb^{-1}. The vector resonance is produced at large transverse momenta, with its decay products merged into a single jet. The resulting signature is a peak over background in the distribution of the invariant mass of the jet. The results are interpreted in the framework of a leptophobic vector resonance and no evidence is found for such particles in the mass range of 100-300 GeV. Upper limits at 95% confidence level on the production cross section are presented in a region of mass-coupling phase space previously unexplored at the LHC. The region below 140 GeV has not been explored by any previous experiments.

Search for physics beyond the standard model in events with two leptons of same sign, missing transverse momentum, and jets in proton-proton collisions at s = 13 TeV

A data sample of events from proton-proton collisions with two isolated same-sign leptons, missing transverse momentum, and jets is studied in a search for signatures of new physics phenomena by the CMS Collaboration at the LHC. The data correspond to an integrated luminosity of 35.9fb - 1 , and a center-of-mass energy of 13TeV . The properties of the events are consistent with expectations from standard model processes, and no excess yield is observed. Exclusion limits at 95% confidence level are set on cross sections for the pair production of gluinos, squarks, and same-sign top quarks, as well as top-quark associated production of a heavy scalar or pseudoscalar boson decaying to top quarks, and on the standard model production of events with four top quarks. The observed lower mass limits are as high as 1500GeV for gluinos, 830GeV for bottom squarks. The excluded mass range for heavy (pseudo)scalar bosons is 350-360 (350-410)GeV . Additionally, model-independent limits in several topological regions are provided, allowing for further interpretations of the results.

Study of Jet Quenching with Z+jet Correlations in Pb-Pb and pp Collisions at sqrt[s]_{NN}=5.02 TeV

The production of jets in association with Z bosons, reconstructed via the μ^{+}μ^{-} and e^{+}e^{-} decay channels, is studied in pp and, for the first time, in Pb-Pb collisions. Both data samples were collected by the CMS experiment at the LHC, at a nucleon-nucleon center-of-mass energy of 5.02 TeV. The Pb-Pb collisions were analyzed in the 0%-30% centrality range. The back-to-back azimuthal alignment was studied in both pp and Pb-Pb collisions for Z bosons with transverse momentum p_{T}^{Z}>60  GeV/c and a recoiling jet with p_{T}^{jet}>30  GeV/c. The p_{T} imbalance x_{jZ}=p_{T}^{jet}/p_{T}^{Z}, as well as the average number of jet partners per Z, R_{jZ}, was studied in intervals of p_{T}^{Z}. The R_{jZ} is found to be smaller in Pb-Pb than in pp collisions, which suggests that in Pb-Pb collisions a larger fraction of partons associated with the Z bosons fall below the 30  GeV/c p_{T}^{jet} threshold because they lose energy.

Measurement of the jet mass in highly boosted [Formula: see text] events from pp collisions at [Formula: see text][Formula: see text]

The first measurement of the jet mass [Formula: see text] of top quark jets produced in [Formula: see text] events from pp collisions at [Formula: see text] [Formula: see text] is reported for the jet with the largest transverse momentum [Formula: see text] in highly boosted hadronic top quark decays. The data sample, collected with the CMS detector, corresponds to an integrated luminosity of 19.7[Formula: see text]. The measurement is performed in the lepton+jets channel in which the products of the semileptonic decay [Formula: see text] with [Formula: see text] where [Formula: see text] is an electron or muon, are used to select [Formula: see text] events with large Lorentz boosts. The products of the fully hadronic decay [Formula: see text] with [Formula: see text] are reconstructed using a single Cambridge-Aachen jet with distance parameter [Formula: see text], and [Formula: see text] [Formula: see text]. The [Formula: see text] cross section as a function of [Formula: see text] is unfolded at the particle level and is used to test the modelling of highly boosted top quark production. The peak position of the [Formula: see text] distribution is sensitive to the top quark mass [Formula: see text], and the data are used to extract a value of [Formula: see text] to assess this sensitivity.

Measurement of double-differential cross sections for top quark pair production in pp collisions at [Formula: see text][Formula: see text] and impact on parton distribution functions

Normalized double-differential cross sections for top quark pair ([Formula: see text]) production are measured in pp collisions at a centre-of-mass energy of 8[Formula: see text] with the CMS experiment at the LHC. The analyzed data correspond to an integrated luminosity of 19.7[Formula: see text]. The measurement is performed in the dilepton [Formula: see text] final state. The [Formula: see text] cross section is determined as a function of various pairs of observables characterizing the kinematics of the top quark and [Formula: see text] system. The data are compared to calculations using perturbative quantum chromodynamics at next-to-leading and approximate next-to-next-to-leading orders. They are also compared to predictions of Monte Carlo event generators that complement fixed-order computations with parton showers, hadronization, and multiple-parton interactions. Overall agreement is observed with the predictions, which is improved when the latest global sets of proton parton distribution functions are used. The inclusion of the measured [Formula: see text] cross sections in a fit of parametrized parton distribution functions is shown to have significant impact on the gluon distribution.

Measurement of the top quark mass using single top quark events in proton-proton collisions at [Formula: see text] TeV

A measurement of the top quark mass is reported in events containing a single top quark produced via the electroweak t channel. The analysis is performed using data from proton-proton collisions collected with the CMS detector at the LHC at a centre-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 19.7 fb[Formula: see text]. Top quark candidates are reconstructed from their decay to a [Formula: see text] boson and a b quark, with the [Formula: see text] boson decaying leptonically to a muon and a neutrino. The final state signature and kinematic properties of single top quark events in the t channel are used to enhance the purity of the sample, suppressing the contribution from top quark pair production. A fit to the invariant mass distribution of reconstructed top quark candidates yields a value of the top quark mass of [Formula: see text]. This result is in agreement with the current world average, and represents the first measurement of the top quark mass in event topologies not dominated by top quark pair production, therefore contributing to future averages with partially uncorrelated systematic uncertainties and a largely uncorrelated statistical uncertainty.

Searches for pair production of third-generation squarks in [Formula: see text][Formula: see text] pp collisions

Searches are presented for direct production of top or bottom squark pairs in proton-proton collisions at the CERN LHC. Two searches, based on complementary techniques, are performed in all-jet final states that are characterized by a significant imbalance in transverse momentum. An additional search requires the presence of a charged lepton isolated from other activity in the event. The data were collected in 2015 at a centre-of-mass energy of 13[Formula: see text] with the CMS detector and correspond to an integrated luminosity of 2.3[Formula: see text]. No statistically significant excess of events is found beyond the expected contribution from standard model processes. Exclusion limits are set in the context of simplified models of top or bottom squark pair production. Models with top and bottom squark masses up to 830 and 890[Formula: see text], respectively, are probed for light neutralinos. For models with top squark masses of 675[Formula: see text], neutralino masses up to 260[Formula: see text] are excluded at 95% confidence level.

A search for new phenomena in pp collisions at [Formula: see text] in final states with missing transverse momentum and at least one jet using the [Formula: see text] variable

A search for new phenomena is performed in final states containing one or more jets and an imbalance in transverse momentum in pp collisions at a centre-of-mass energy of 13[Formula: see text]. The analysed data sample, recorded with the CMS detector at the CERN LHC, corresponds to an integrated luminosity of 2.3[Formula: see text]. Several kinematic variables are employed to suppress the dominant background, multijet production, as well as to discriminate between other standard model and new physics processes. The search provides sensitivity to a broad range of new-physics models that yield a stable weakly interacting massive particle. The number of observed candidate events is found to agree with the expected contributions from standard model processes, and the result is interpreted in the mass parameter space of fourteen simplified supersymmetric models that assume the pair production of gluinos or squarks and a range of decay modes. For models that assume gluino pair production, masses up to 1575 and 975[Formula: see text] are excluded for gluinos and neutralinos, respectively. For models involving the pair production of top squarks and compressed mass spectra, top squark masses up to 400[Formula: see text] are excluded.