Cyanine dye-embedded fluorescent film for ratiometric pH measurement.

The precise monitoring of pH is critical in various applications, particularly in biology-related areas. In this work, we report the synthesis and characterization of a novel cyanine-based fluorescent pH sensor with a pK around 6. This pH-sensitive dye features a cyanine chromophore coupled to a piperazine moiety, which modulates the protonation equilibrium and thus the optical response.

strategy to design an efficient organic photoswitch based on excited-state cation transfer.

A new class of photoswitches and the corresponding elementary photoinduced reaction, the so-called Excited-State Cation Transfer (ESCT), are investigated. This reaction relies on an intramolecular photo-release/photo-complexation of cation: after irradiation, the cation is translocated from a complexation site 1 to a site 2 during the excited state lifetime. Our purpose is thus to develop a computational strategy based on Density Functional theory (DFT) and its time-dependent counterpart (TD-DFT) to improve the different properties of the ESCT photoswitches, namely (i) the ground state complexation constant , (ii) the excited state complexation constant *, (iii) the photoejection properties and (iv) the population of the triplet states from a singlet state intersystem crossing to increase the lifetime of the excited state.

A Highly Sensitive and Selective Optical Sensor for the On-Line Detection of Cesium in Water.

In this study, we have undertaken the development of two fluorescent sensors based on calixarene compounds for the purpose of detecting cesium in water. By introducing the sulfonate functional groups, we have considerably improved the water solubility of sensors, enabling complete dissolution of products in aqueous media and direct analysis of polluted water samples. Through rigorous experiments, we have demonstrated that the complexation of Cs ions with sensors and in water leads to a remarkable enhancement of fluorescence.

Physiological synaptic activity and recognition memory require astroglial glutamine.

Presynaptic glutamate replenishment is fundamental to brain function. In high activity regimes, such as epileptic episodes, this process is thought to rely on the glutamate-glutamine cycle between neurons and astrocytes. However the presence of an astroglial glutamine supply, as well as its functional relevance in vivo in the healthy brain remain controversial, partly due to a lack of tools that can directly examine glutamine transfer.

Volvulus of the appendix secondary to appendicular mucocele.

A 44-year-old woman presented with appendicular volvulus secondary to an appendicular mucocele. Appendicular volvulus symptomatology is similar to that of acute appendicitis. Diagnosis is often interoperative.

Thermally Activated Delayed Photoluminescence: Deterministic Control of Excited-State Decay.

Thermally activated photophysical processes are ubiquitous in numerous organic and metal-organic molecules, leading to chromophores with excited-state properties that can be considered an equilibrium mixture of the available low-lying states. Relative populations of the equilibrated states are governed by temperature. Such molecules have been devised as high quantum yield emitters in modern organic light-emitting diode technology and for deterministic excited-state lifetime control to enhance chemical reactivity in solar energy conversion and photocatalytic schemes.

Singlet oxygen stimulus for switchable functional organic cages.

Molecular cages and incorporating a 9,10-diphenylanthracene (DPA) chromophore were synthesized through a templated ring-closure metathesis approach that allows variation in cavity size through the introduction of up to three different pillars. Reversible Diels-Alder reaction between the DPA moiety and photogenerated singlet oxygen smoothly converted and to the corresponding endoperoxide cages and , which are converted back to and upon heating. Endoperoxide formation constitutes a reversible covalent signal that combines structural changes in the interior of the cage with introduction of two additional coordination sites.

Thermally activated delayed photoluminescence from pyrenyl-functionalized CdSe quantum dots.

The generation and transfer of triplet excitons across semiconductor nanomaterial-molecular interfaces will play an important role in emerging photonic and optoelectronic technologies, and understanding the rules that govern such phenomena is essential. The ability to cooperatively merge the photophysical properties of semiconductor quantum dots with those of well-understood and inexpensive molecular chromophores is therefore paramount. Here we show that 1-pyrenecarboxylic acid-functionalized CdSe quantum dots undergo thermally activated delayed photoluminescence.

Delayed Molecular Triplet Generation from Energized Lead Sulfide Quantum Dots.

The generation and transfer of triplet excitons across the molecular-semiconductor interface represents an important technological breakthrough featuring numerous fundamental scientific questions. This contribution demonstrates curious delayed formation of TIPS-pentacene molecular triplet excitons bound on the surface of PbS nanocrystals mediated through the initial production of a proposed charge transfer intermediate following selective excitation of the PbS quantum dots. Ultrafast UV-vis and near-IR transient absorption spectroscopy was used to track the dynamics of the initial PbS exciton quenching as well as time scale of the formation of molecular triplet excited states that persisted for 10 μs on the PbS surface, enabling subsequent energy and electron transfer reactivity.

Efficient Generation of Long-Lived Triplet Excitons in 2D Hybrid Perovskite.

Triplet excitons form in quasi-2D hybrid inorganic-organic perovskites and diffuse over 100 nm before radiating with >11% photoluminescence quantum efficiency (PLQE) at low temperatures.

Bowel dysfunction after anastomotic leakage in laparoscopic sphincter-saving operative intervention for rectal cancer: A case-matched study in 46 patients using the Low Anterior Resection Score.

Background: After sphincter-saving operation for rectal cancer, the impact of anastomotic leakage on function has been well studied. The purpose of the present work was to assess the influence of symptomatic and asymptomatic anastomotic leakage on bowel function and health-related quality of life using the Low Anterior Resection Syndrome score and the disease-specific questionnaire European Organization for Research and Treatment of Quality of Life Questionnaire for Colorectal Cancer.

Methods: The study was a case-matched study with multiple controls per case in a variable ratio from a prospectively maintained database conducted at a tertiary, colorectal operation referral center.

Oncological impact of anastomotic leakage after laparoscopic mesorectal excision.

Background: The effect of anastomotic leakage on oncological outcomes after total mesorectal excision (TME) is controversial. This study aimed to assess the influence of symptomatic and asymptomatic anastomotic leakage on oncological outcomes after laparoscopic TME.

Methods: All patients who underwent restorative laparoscopic TME for rectal adenocarcinoma with curative intent from 2005 to 2014 were identified from an institutional database.

Liquid PEG Polymers Containing Antioxidants: A Versatile Platform for Studying Oxygen-Sensitive Photochemical Processes.

This article proposes the exploitation of widely available, inexpensive, innocuous "green" liquid polyethylene glycol (PEG) polymers containing the oxygen scavenger oleic acid (OA) as promising media for studying oxygen-sensitive photochemical processes. Here we report the successful application of this media to detailed investigations of triplet-sensitized photochemical upconversion, previously established as being readily poisoned by dissolved oxygen. Three different PEG materials were investigated with increasing molecular weight from 200 to 600 g/mol, coded as PEG-200, PEG-400, and PEG-600.

Is the benefit of laparoscopy maintained in elderly patients undergoing rectal cancer resection? An analysis of 446 consecutive patients.

Background: Several studies showed that age is significantly associated with impaired outcomes after open colorectal surgery. However, very few data exist on laparoscopic rectal cancer surgery in elderly patients. The aim of this study was to assess operative results of laparoscopic rectal cancer surgery according to age.

Direct observation of triplet energy transfer from semiconductor nanocrystals.

Triplet excitons are pervasive in both organic and inorganic semiconductors but generally remain confined to the material in which they originate. We demonstrated by transient absorption spectroscopy that cadmium selenide semiconductor nanoparticles, selectively excited by green light, engage in interfacial Dexter-like triplet-triplet energy transfer with surface-anchored polyaromatic carboxylic acid acceptors, extending the excited-state lifetime by six orders of magnitude. Net triplet energy transfer also occurs from surface acceptors to freely diffusing molecular solutes, further extending the lifetime while sensitizing singlet oxygen in an aerated solution.

Bioprosthetic mesh reinforcement during temporary stoma closure decreases the rate of incisional hernia: A blinded, case-matched study in 94 patients with rectal cancer.

Background: This case-matched study aimed to assess the feasibility and the potential benefits of placement of a prophylactic bioprosthetic collagen porcine mesh during closure of the temporary ileostomy after total mesorectal excision (TME) for rectal cancer.

Methods: From September 2012 to March 2013, 30 consecutive patients underwent placement of a retromuscular bioprosthetic mesh in the abdominal wall during closure of a diverting ileostomy after sphincter-saving laparoscopic TME for rectal cancer (mesh group). These 30 patients were matched individually to all identical patients who underwent a closure of the ileostomy without mesh after laparoscopic TME extracted from our prospective database (control group).

Template effects and supramolecular control of photoreactions in solution.

A review of supramolecular and template effects on photochemical reactions in solution is presented. Photoinduced [2+2] and [4+4] cycloaddition reactions, isomerization, electron transfer and radical processes are covered, as well as examples of DNA photoligation.

Does anastomotic leakage impair functional results and quality of life after laparoscopic sphincter-saving total mesorectal excision for rectal cancer? A case-matched study.

Purpose: Anastomotic leakage (AL) after total mesorectal excision (TME) for rectal cancer is suspected to alter function. However, very few reports have been devoted to this problem. The aim of this study was to assess the influence of AL on function and quality of life (QoL) after laparoscopic TME for cancer.

Unexplained polyposis: a challenge for geneticists, pathologists and gastroenterologists.

Two main colorectal polyposis syndromes have been described, familial adenomatous polyposis and MUTYH-associated polyposis syndromes. Some polyposis remains unexplained: 20% of adenomatous polyposis and serrated polyposis. The aim of this study was to evaluate in a cohort of patients with unexplained polyposis whether a genetic defect could be detected.

Frequent mutation in North African patients with MUTYH-associated polyposis.

MUTYH-associated polyposis (MAP) has been characterized as an autosomal recessive disease predisposing to a variable number of colorectal adenomas with a high risk of cancer. Numerous studies have indicated that two missense mutations (Y179C and G396D) account for about 80% of MUTYH allelic variants in Europeans. Ethnic and geographic differences in the mutation spectrum have been observed.

[Evaluation of stress in surgical trainees: prospective study of heart rate during laparoscopic cholecystectomy].

Introduction: Surgical training is stressful, particularly in the operating room setting. The purpose of the study is to evaluate and quantitate intra-operative stress in surgical trainees.

Material: and methods: Cardiac rate was used as a measure of stress during surgical cases; surgical residents serving as the primary surgeon and assistant during 21 laparoscopic cholecystectomies underwent telemetry monitoring.