On a conjecture of Bennewitz, and the behaviour of the Titchmarsh-Weyl matrix near a pole

For any real limit-$n$ $2n$th-order selfadjoint linear differential expression on $[0,\infty)$, Titchmarsh- Weyl matrices $M(\lambda)$ can be defined. Two matrices of particu lar interest are the matrices $M_D(\lambda)$ and $M_N(\lambda)$ assoc iated respectively with Dirichlet and Neumann boundary conditions at $x=0$. These satisfy $M_D(\lambda) = -M_{N}(\lambda)^{-1}$. It is known that when these matrices have poles (which can only lie on the real axis) the existence of valid HELP inequalities depends on their behaviour in the neighbourhood of these poles. We prove a conjecture of Bennewitz and use it, together with a new algorithm for computing the Laurent expansion of a Titchmarsh-Weyl matrix in the neighbourhood of a pole, to investigate the existence of HELP inequalities for a number of differential equations which have so far proved awkward to analys

Enhanced crystallinity and film retention of P3HT thin-films for efficient organic solar cells by use of preformed nanofibers in solution

We report the preparation of films of poly(3-hexylthiophene) nanofibers suitable for fabrication of efficient multilayer solar cells by successive deposition of donor and acceptor layers from the same solvent. The nanofibers are obtained by addition of di-tert-butyl peroxide (DTBP) to a solution of P3HT in chlorobenzene. Interestingly, by varying the concentration of DTBP we are able to control both crystallinity and film retention of the spin-cast films. We also investigate the influence of the DTBP-induced crystallization on charge transport by thin-film transistor measurements, and find a more than five-fold increase in the hole mobility of nanofiber films compared to pure P3HT. We attribute this effect to the synergistic effects of increased crystallinity of the fibers and the formation of micrometer-sized fiber networks. We further demonstrate how it is possible to make use of the high film retention to fabricate photovoltaic devices by subsequent deposition of [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) from a chlorobenzene solution on top of the nanofiber film. The presence of a relatively large crystalline phase strongly affects the diffusion behavior of PCBM into the P3HT film, resulting in a morphology which is different from that of common bulk heterojunction solar cells and resembles a bilayer structure, as can be inferred from comparison of the external quantum efficiency spectra. However, a high power conversion efficiency of 2.3% suggests that there is still a significant intermixing of the two materials taking place

Recurrence and progression of periodontitis and methods of management in long-term care: A systematic review and meta-analysis

Aim: To systematically review the literature to evaluate the recurrence of disease of people in long-term supportive periodontal care (SPC), previously treated for periodontitis, and determine the effect of different methods of managing recurrence. The review focused on stage IV periodontitis. Materials and methods: An electronic search was conducted (until May 2020) for prospective clinical trials. Tooth loss was the primary outcome. Results: Twenty-four publications were retrieved to address recurrence of disease in long-term SPC. Eight studies were included in the meta-analyses for tooth loss, and three studies for disease progression/recurrence (clinical attachment level [CAL] loss ≥2 mm). For patients in SPC of 5–20 years, prevalence of losing more than one tooth was 9.6% (95% confidence interval [CI] 5%–14%), while experiencing more than one site of CAL loss ≥2 mm was 24.8% (95% CI 11%–38%). Six studies informed on the effect of different methods of managing recurrence, with no clear evidence of superiority between methods. No data was found specifically for stage IV periodontitis. Conclusions: A small proportion of patients with stage III/IV periodontitis will experience tooth loss in long-term SPC (tendency for greater prevalence with time). Regular SPC appears to be important for reduction of tooth loss. No superior method to manage disease recurrence was found

Complications and treatment errors in periodontal therapy in medically compromised patients

Patients who are medically compromised may be at an increased risk of complications and treatment errors following periodontal therapy. A review of the evidence on the topic is presented, in relation to the type of complication reported, of periodontal treatment, and of patients' medical status. Further, a framework for risk assessment and appropriate treatment modifications is introduced, with the aim of facilitating the management of patients with existing comorbidities and reducing the incidence of treatment complications

Hyaluronan-based pericellular matrix: substrate electrostatic charges and early cell adhesion events

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Value of a Multidisciplinary Approach in Sinonasal Inverted Papilloma with Extensive Ossification

Objective: Background: Casa Report: Conclusions: Rare disease Inverted papilloma is a benign epithelial lesion of the nasal cavities. Although commonly encountered in clinical practice, it rarely presents with extensive ossification and few cases have been described in the literature. Herein, we describe the case of a 51-year-old man who presented to clinical attention for persistent right nasal obstruction. Magnetic resonance imaging (MRI) and computed tomography (CT) scans of the facial bones showed a lobated lesion with ossification occupying most of the right nasal cavity. The lesion was removed by endoscopic sinus surgery, leaving the surrounding bone structures intact. On pathological examination, mature bone tissue was found within an inverted papilloma. The pathologist contacted the surgeon, who confirmed that no healthy bone tissue was removed during the procedure. Therefore, a diagnosis of inverted papilloma with ossification could be made without the use of ancillary techniques. Inverted papilloma with ossification is a common lesion with a rare feature. Our report investigates the diagnostic difficulties of a paradigmatic case, highlighting the importance of multidisciplinary teamwork in reach-ing the final diagnosis

A phase II study of induction chemotherapy followed by concurrent chemoradiotherapy in elderly patients with locally advanced non-small-cell lung cancer.

The optimal management of unresectable locally advanced non-small-cell lung cancer in older patients has not been defined to date. The present phase II study was planned to evaluate the activity and safety of platinum-based induction chemotherapy followed by concurrent chemoradiotherapy in elderly patients with locally advanced non-small-cell lung cancer. Patients received two cycles of paclitaxel (175 mg/m) and carboplatin (area under the curve: 5) day 1, every 3 weeks. Chemoradiotherapy (thoracic radiation therapy) was initiated on day 42 and consisted of 1.8 Gy daily, five times per week over 5 weeks (45.0 Gy target dose) followed by 10 2.0 Gy daily fractions. Concomitant chemotherapy was weekly paclitaxel 50 mg/mq followed by weekly carboplatin at an area under the curve of 2. The eligibility for patients: age 70 or older and histologically documented untreated non-small-cell lung cancer, locally advanced, unresectable, stage III A N2 bulky or III B. Thirty consecutive patients were enrolled onto the study. The median age was 73 (range 70-76). According to the intention-to-treat analysis, 1 month after the end of combined chemoradiotherapy, we observed complete and partial responses in one and 19 of the 30 patients, respectively, for an overall response rate of 66% (95% confidence interval, 45-76%). Median progression-free survival was 8.7 months (95% confidence interval, 3.4-37.8) and median survival was 15 months (95% confidence interval, 4.2-52.1). During the treatment, 12 patients (40.0%) experienced grade 3-4 neutropenia, two patients neutropenic fever, and three patients grade 3 anaemia and grade 3 thrombocytopenia, respectively. Grade 3 oesophagitis, during concomitant radiotherapy, was observed in six patients (20.0%). No treatment-related mortality was reported. The investigated sequential approach including induction chemotherapy followed by concurrent chemoradiotherapy appears safe and seems a reasonable chance for the treatment of locally advanced non-small-cell lung cancer in the elderly population