Generalized φ\varphi-pullback attractors for evolution processes and application to a nonautonomous wave equation

In this work we define the generalized $\varphi$-pullback attractors for evolution processes in complete metric spaces, which are compact and positively invariant families, such that they pullback attract bounded sets with a rate determined by a decreasing function $\varphi$ that vanishes at infinity. We find conditions under which a given evolution process has a generalized $\varphi$-pullback attractor, both in the discrete and in the continuous cases. We present a result for the special case of generalized polynomial pullback attractors, and apply it to obtain such an object for a nonautonomous wave equation.Comment: 32 page

Ruthenium (0) complexes with NHC tetrazolylidene ligands: Synthesis, characterization and reactivity

Here we present two new phenyl-tetrazolylidene carbenes as ligands in non-mesoionic (1,4-substitution pattern) and mesoionic (1,3-substitution pattern) tetrazolylidene-cyclopentadienone ruthenium(0) complexes namely 1 and 2 respectively. The complexes have been obtained in good yield and fully characterized; X-ray structure determination confirmed the binding mode of the ligand for 2. Reactivity studies has been performed in order to shed light on the fact that the phenyl substituent position in the heterocyclic ligand can seriously change complexes behavior and stabilit

Therapeutic approach in glioblastoma multiforme with primitive neuroectodermal tumor components: case report and review of the literature

Glioblastoma multiforme (GBM) is the most common and aggressive malignant glioma that is treated with first-line therapy, using surgical resection followed by local radiotherapy and concomitant/adjuvant temozolomide (TMZ) treatment. GBM is characterised by a high local recurrence rate and a low response to therapy. Primitive neuroectodermal tumour (PNET) of the brain revealed a low local recurrence rate; however, it also exhibited a high risk of cerebrospinal fluid (CSF) dissemination. PNET is treated with surgery followed by craniospinal irradiation (CSI) and platinum-based chemotherapy in order to prevent CSF dissemination. GBM with PNET-like components (GBM/PNET) is an emerging variant of GBM, characterised by a PNET-like clinical behaviour with an increased risk of CSF dissemination; it also may benefit from platinum-based chemotherapy upfront or following failure of GBM therapy. The results presented regarding the management of GBM/PNET are based on case reports or case series, so a standard therapeutic approach for GBM/PNET is not defined, constituing a challenging diagnostic and therapeutic dilemma. In this report, a case of a recurrent GBM/PNET treated with surgical resection and radiochemotherapy as Stupp protocol, and successive platinum-based chemotherapy due to the development of leptomeningeal dissemintation and an extracranial metastasis, is discussed. A review of the main papers regarding this rare GBM variant and its therapeutic approach are also reported. In conclusion, GBM/PNET should be treated with a multimodal approach including surgery, chemoradiotherapy, and/or the early introduction of CSI and platinum-based chemotherapy upfront or at recurrence

Platelet-Rich Plasma combined with a sterile 3D polylactic acid scaffold for postoperative management of complete hoof wall resection for keratoma in four horses.

Keratoma is a non-malignant horse tumour that grows in the space between the horn of the hoof and the distal phalanx. Keratoma causes lameness in the horse, and surgical excision is the treatment of choice. Four horses underwent removal of a keratoma by complete hoof wall resection. The remaining wound was treated with Platelet-Rich Plasma (PRP) combined with a sterile 3D polylactic acid scaffold. The PRP was applied at 3, 6, 9, 12, 15 and 18 days postoperatively. The surgical site was cleaned with gauzes and swabs soaked in Ringer’s lactate solution before applying PRP and the foot bandage. Healthy granulation tissue developed at 6-21 days postoperatively. The hoof wall defect was completely filled with new hoof wall within 6-8 months after surgery. All horses returned to their previous exercise level and no recurrence of lameness was reported by the owner

A retrospective whole-genome sequencing analysis of carbapenem and colistin-resistant klebsiella pneumoniae nosocomial strains isolated during an MDR surveillance program

Multidrug-resistant Klebsiella pneumoniae (MDR Kp), in particular carbapenem-resistant Kp (CR-Kp), has become endemic in Italy, where alarming data have been reported on the spread of colistin-resistant CR-Kp (CRCR-Kp). During the period 2013–2014, 27 CRCR-Kp nosocomial strains were isolated within the Modena University Hospital Policlinico (MUHP) multidrug resistance surveillance program. We retrospectively investigated these isolates by whole-genome sequencing (WGS) analysis of the resistome, virulome, plasmid content, and core single nucleotide polymorphisms (cSNPs) in order to gain insights into their molecular epidemiology. The in silico WGS analysis of the resistome revealed the presence of genes, such as blaKPC, related to the phenotypically detected resistances to carbapenems. Concerning colistin resistance, the plasmidic genes mcr 1–9 were not detected, while known and new genetic variations in mgrB, phoQ, and pmrB were found. The virulome profile revealed the presence of type-3 fimbriae, capsular polysaccharide, and iron acquisition system genes. The detected plasmid replicons were classified as IncFIB(pQil), IncFIB(K), ColRNAI, IncX3, and IncFII(K) types. The cSNPs genotyping was consistent with the multi locus sequence typing (MLST) and with the distribution of mutations related to colistin resistance genes. In a nosocomial drug resistance surveillance program, WGS proved to be a useful tool for elucidating the spread dynamics of CRCR-Kp nosocomial strains and could help to limit their diffusion

Prolonged RT-PCR test positivity in hemodialysis patients with COVID-19

Background: The weakened immune system of patients on hemodialysis (HD) may prolong SARS-CoV-2 infection compared to the general population. Current international guidelines recommend ending isolation in conjunction with serial testing in moderately and severely immunocompromised subjects. This study aimed to estimate SARS-CoV-2 infectivity by measuring RT-PCR test positivity in HD patients. A comparison between RT-PCR test and cycle threshold (Ct) value has been performed as a secondary endpoint. Methods: A single-center retrospective study was conducted at the University of Modena (Italy) from March 2020 to October 2022. Only patients on chronic HD therapy with COVID-19 were enrolled in the study. In our HD Center, two negative nasopharyngeal reverse transcription polymerase chain reaction (RT-PCR) results were used to end quarantine in this population. SARS-CoV-2 RT-PCR test positivity duration measured the time elapsed from a positive RT-PCR to a second negative test. Ct cut-off of 35 cycles was used to definite “high Ct value,” a condition characterized by a large number of cycles of PCR amplification to register a positive RT-PCR test. Results: During the observational period, 159 cases of SARS-CoV-2 infections were diagnosed in 151 patients. Median age was 70.1 (54.3–81.6) years and males accounted for 59.6% of the COVID-19 population. Median duration of SARS-CoV-2 RT-PCR test positivity on the nasal mucosa accounted for 30 (IQR, 21–40.5) days. Unvaccinated patients experienced significantly longer RT-PCR test positivity compared to vaccinated patients (42 [IQR,31–56] vs. 28 [IQR,20–35.7] days; p = < 0.001). The use of high Ct value, a laboratory surrogate of SARS-CoV-2 replication, anticipated a negative RT-PCR test of 9 (IQR, 6–12) days. Multivariate linear regression analysis showed that increased age (β coefficient 0.31; confidence interval [CI] 95%, 0.14—0.43; p = < 0.001) and the lack of anti-SARS-CoV-2 vaccination (β 0.49 CI95%, 11.9–22.5; p = < 0.001) were predictors of a prolonged RT-PCR positivity. Conclusions: Patients with COVID-19 on HD had prolonged RT-PCR test positivity. The adoption of “high Ct value” criteria led to a significant reduction in the duration of RT-PCR test positivity compared to the use of the classical nucleic acid amplification test. In our study, the lack of SARS-CoV-2 vaccination and older age were independently associated with a longer RT-PCR positivity

On the Relationship Between Ultrasonic and Micro-Structural Properties of Imperfect Interfaces in Layered Solids

The interaction of ultrasonic waves with interfaces formed by two non-conforming, rough surfaces in contact has been the subject of numerous investigations [1–10]. The motivations behind these studies have been various: from the assessment of the real area of contact between two rough surfaces [1], to the modeling of crack closure near the tip of a fatigue crack [4]; from the identification of the nature of interfacial imperfections in kissing and partial bonds [6], to the generation of ultrasonic waves [8]. In most of these studies, the characterization of the interfacial properties has been attempted by studying the reflection of longitudinal and shears waves at normal incidence. Only recently, the problem concerning the interaction of ultrasonic waves with realistic complex systems such as that formed by two neighboring imperfect interfaces has been addressed. Lavrentyev and Rokhlin [9, 10] used ultrasonic spectroscopy to evaluate the interfacial conditions from the spectra of longitudinal and shear waves reflected normally from the interfaces

The effect of crack orientation on the nonlinear interaction of a P wave with an S wave

Cracks, joints, fluids, and other pore-scale structures have long been hypothesized to be the cause of the large elastic nonlinearity observed in rocks. It is difficult to definitively say which pore-scale features are most important, however, because of the difficulty in isolating the source of the nonlinear interaction. In this work, we focus on the influence of cracks on the recorded nonlinear signal and in particular on how the orientation of microcracks changes the strength of the nonlinear interaction. We do this by studying the effect of orientation on the measurements in a rock with anisotropy correlated with the presence and alignment of microcracks. We measure the nonlinear response via the traveltime delay induced in a low-amplitude P wave probe by a high-amplitude S wave pump. We find evidence that crack orientation has a significant effect on the nonlinear signal

Is it cheating or learning the craft of writing? Using Turnitin to help students avoid plagiarism

Plagiarism is a growing problem for universities, many of which are turning to software detection for help in detecting and dealing with it. This paper explores issues around plagiarism and reports on a study of the use of Turnitin in a new university. The purpose of the study was to inform the senior management team about the plagiarism policy and the use of Turnitin. The study found that staff and students largely understood the university’s policy and Turnitin’s place within it, and were very supportive of the use of Turnitin in originality checking. Students who had not used Turnitin were generally keen to do so. The recommendation to the senior management team, which was implemented, was that the use of Turnitin for originality checking should be made compulsory where possible - at the time of the study the use of Turnitin was at the discretion of programme directors. A further aim of the study was to contribute to the sector’s body of knowledge. Prevention of plagiarism through education is a theme identified by Badge and Scott (2009) who conclude an area lacking in research is "investigation of the impact of these tools on staff teaching practices". Although a number of recent studies have considered educational use of Turnitin they focus on individual programmes or subject areas rather than institutions as a whole and the relationship with policy