Polypyridyl ligands as a versatile platform for solid-state light-emitting devices.

The replacement of inorganic semiconductors with molecule-based compounds for applications in current-to-light conversion has led to a significant increase in interdisciplinary collaborations worldwide, affording new improved organic-light emitting diodes (OLEDs) ripe for commercial applications, as well as light-emitting electrochemical cells (LECs) that have recently started to head to the market. This review highlights the role that transition metal coordination complexes (TMCs) have played in advancing the field of molecular electronics, from early conception to the advanced development of several polypyridyl complexes currently pursued for both OLED and LEC concepts. In this context, the design and synthesis of Ir(iii), Pt(ii), Cu(i) and Ag(i) complexes as the emissive components of OLEDs and LECs are thoughtfully presented. We discuss how molecular design is pivotal for fine-tuning color and optimizing power efficiencies, highlighting the key roles of the metal, cyclometalate, and ancillary polypyridyl ligands. We provide insight into the strategies exploited for the development of new, improved emitters and their fabrication into OLEDs/LECs with high external quantum efficiencies and stabilities. In addition, we have surveyed the remarkable photophysical properties of third generation TMCs capable of undergoing thermally activated delayed fluorescence (TADF). Since previous reviews of TADF materials are strongly biased towards organic-based systems, this overview compliments other synopses of light emitting TADF materials. Finally, we shed light onto the conceptual challenges that still need to be overcome to advance the rational design of TMC-based TADF emitters with tunable ligands and the subsequent fabrication of OLEDs/LECs, which are tailor-made for each specific application.

Transition Metal Single-Molecule Magnets: A {Mn31} Nanosized Cluster with a Large Energy Barrier of ∼60 K and Magnetic Hysteresis at ∼5 K.

The first {Mn31} cluster (1) has been prepared from carboxylate ions and the chelating/bridging ligand α-methyl-2-pyridine-methanol. Compound 1 possesses a unique nanosized structural topology with one of the largest energy barriers reported to-date for high-nuclearity 3d-metal clusters. Single-crystal magnetic hysteresis studies reveal the presence of hysteresis loops below 5 K, one of the highest temperatures below which molecular hysteresis has been observed for 3d-based SMMs.

Effects of body electroacupuncture on plasma leptin concentrations in obese and overweight people in Iran: a randomized controlled trial.

BACKGROUND: The prevalence of obesity, a major public health problem, is increasing in many countries, including Iran. Leptin, a peptide hormone that is released from adipocytes, is a major factor in appetite regulation. Levels of plasma leptin increase with increased body fat mass (BFM). Research has found acupuncture to be effective both in weight loss and suppression of appetite. Although a few studies have reported the effect of body and ear acupuncture on leptin levels, researchers have performed few studies on the effect of body electroacupuncture in humans. OBJECTIVE: The research team examined the effects of body electroacupuncture and a low-calorie diet on plasma leptin in obese and overweight individuals with an excess (phlegm-dampness or phlegm-heat) or deficiency (spleen/stomach qi deficiency or primary qi deficiency) pattern according to Chinese medicine. DESIGN: The research team randomly assigned participants to one of two groups, intervention or control. SETTING: This study occurred in the nutritional clinic at Ghaem Hospital in Mashhad, Iran. PARTICIPANTS: Participants were individuals (N = 86) between 18 and 65 years of age with body mass indexes (BMI) between 25 and 45 kg/m2. INTERVENTION: The intervention group (n = 47) received actual electroacupuncture, and the control group (n = 47) received sham acupuncture. Both groups consumed a low-calorie diet for 6 weeks. OUTCOME MEASURES: The research team measured plasma leptin, BFM, body weight (BW), and BMI before and after treatment. RESULTS: For participants in the intervention group with both the excess and the deficiency patterns, the research team found a significant reduction in plasma leptin (24.96%, P = .001) and BFM (8.29%, P = .001). In the control group, the team found a less significant reduction in leptin and BFM. The difference between the two groups was significant for leptin (P = .03) but not for BFM (P = .8). CONCLUSIONS: While body electroacupuncture with a low-calorie diet can reduce plasma leptin concentration, the mechanism will require further clarification.

Cell Encapsulation and 3D Bioprinting for Therapeutic Cell Transplantation.

The promise of cell therapy has been augmented by introducing biomaterials, where intricate scaffold shapes are fabricated to accommodate the cells within. In this review, we first discuss cell encapsulation and the promising potential of biomaterials to overcome challenges associated with cell therapy, particularly cellular function and longevity. More specifically, cell therapies in the context of autoimmune disorders, neurodegenerative diseases, and cancer are reviewed from the perspectives of preclinical findings as well as available clinical data. Next, techniques to fabricate cell-biomaterials constructs, focusing on emerging 3D bioprinting technologies, will be reviewed. 3D bioprinting is an advancing field that enables fabricating complex, interconnected, and consistent cell-based constructs capable of scaling up highly reproducible cell-biomaterials platforms with high precision. It is expected that 3D bioprinting devices will expand and become more precise, scalable, and appropriate for clinical manufacturing. Rather than one printer fits all, seeing more application-specific printer types, such as a bioprinter for bone tissue fabrication, which would be different from a bioprinter for skin tissue fabrication, is anticipated in the future.

Prevalence of Depression, Anxiety and Stress Among Patients Discharged from Critical Care Units.

INTRODUCTION: The widespread use of advanced technology and invasive intervention creates many psychological problems for hospitalized patients; it is especially common in critical care units. METHODS: This cross-sectional study was conducted on 310 patients hospitalized in critical care units, using a non-probability sampling method. Data were collected using depression, anxiety, and stress scale (DASS-21) one month after discharge from the hospital. Data analysis was performed using descriptive and inferential statistics. RESULTS: 181 males and 129 females with a mean age (SD) of 55.11(1.62) years were enrolled in the study. The prevalence of depression, anxiety and stress were 46.5, 53.6 and 57.8% respectively, and the depression, anxiety and stress mean (SD) scores were 16.15(1.40), 18.57(1.46), 19.69(1.48), respectively. A statistically significant association was reported between depression, anxiety and stress with an increase in age, the number of children, occupation, education, length of hospital stay, use of mechanical ventilation, type of the critical care unit, and drug abuse. CONCLUSION: The prevalence of depression, anxiety and stress in patients discharged from critical care units was high. Therefore, crucial decisions should be made to reduce depression, anxiety and stress in patients discharged from critical care units by educational strategies, identifying vulnerable patients and their preparation before invasive diagnostic-treatment procedures.

Oxidative addition of tetrathiocins to palladium(0) and platinum(0): a route to dithiolate coordination complexes.

The preparation of a series of 4,4',5,5'-substituted benzo-fused 1,2,5,6-tetrathiocins X2C6H2S4C6H2X2 (1a-1g) were prepared from the reaction of S2Cl2 with 1,2-C6H4X2 (X = OMe, OEt; X2 = OCH2O, OCH2CH2O, OCH2CH2CH2O, MeNC([double bond, length as m-dash]O)NMe, O(CH2CH2O)4). The oxidative addition of 1a-1g to zero-valent Pd2dba3 or Pt2dba3 (dba = dibenzylideneacetone) in the presence of bis (diphenylphosphino)ethane (dppe) resulted in formation of the substituted mononuclear benzenedithiolate complexes M(L)(dppe) [L = dithiolate ligand; 2a-2g (M = Pd) and 3a-3g (M = Pt)] in 37-89% yield based on recrystallized material. Representative examples of M(L)(dppf) [dppf = bis-diphenylphosphinoferrocene; 4a, 4g (M = Pd) and 5g (M = Pt)] were prepared in a similar fashion. The structures of all derivatives were determined by X-ray diffraction, multinuclear NMR and elemental analysis. The reactivity of the two crown ether dithiolate complexes, 2g and 4g, with 1 equivalent of NaBPh4 led to isolation of the 1 : 1 complexes in which the Na+ cation is bound in the macrocyclic crown, [Na(2g)(MeOH)2][BPh4] and [Na(4g)][BPh4] whose structures were determined by X-ray diffraction. Electrochemical studies supported through DFT calculations on the crown ether derivatives revealed a series of ligand-based oxidation waves corresponding to the dithiolate ligand (and dppf for 4g and 5g) whose redox potentials were shifted by ca. +0.1 V on binding to Na+.

Click chemistry as a route to the synthesis of structurally new and magnetically interesting coordination clusters: a {Ni} complex with a trapezoidal prismatic topology.

The synthesis of a new {Ni8} cluster bearing tetrazolate- and azido-bridging ligands, and supported by chelating α-methyl-2-pyridine-methanol (mpmH) groups, is described herein. The reported compound has a unique trapezoidal prismatic topology, resulting from an unexpected in situ click reaction between the MeCN reaction solvent and the N3- ions under mild, room-temperature conditions. Such a click chemistry approach to the preparation of 0-D compounds is relatively unexplored and represents a fruitful strategy for the synthesis of new coordination clusters and molecule-based magnetic materials.

Versatile synthesis of chiral 6-oxoverdazyl radical ligands - new building blocks for multifunctional molecule-based magnets.

A versatile synthetic methodology to access the first family of chiral verdazyl N,N'-chelate ligands is described and exemplified by N,N'-dimethyl-, N,N'-di-isopropyl- and N,N'-diphenyl oxoverdazyls bearing two isomers of the pinene-pyridine functional group. Their physical properties were probed by X-band EPR spectroscopy, cyclic voltammetry and DFT calculations. Preliminary reactivity studies show they can act as N,N'-chelate ligands affording a chiral 1 : 1 complex (3b) with CuCl2, which was characterized by single-crystal X-ray diffraction. Variable temperature EPR studies on (3b) confirm the presence of antiferromagnetic interactions between the spins of the Cu(ii) ion and the verdazyl radical.

Abdominal and auricular acupuncture reduces blood pressure in hypertensive patients.

INTRODUCTION: Hypertension is an important risk factor of cardiovascular disease (CVD), which is associated with premature death, myocardial infarction, stroke, peripheral vascular disease, and renal disease. The goal of the present study was to use a randomized controlled clinical trial to explore and compare the effectiveness of abdominal and auricular acupuncture on blood pressure in 440 subjects with and without obesity. METHODS: Four hundred participants were recruited and randomized to one of four groups: cases and controls receiving auricular acupuncture (204 subjects) and cases and controls receiving abdominal electroacupuncture (196 subjects). Blood pressure and anthropometric parameters were measured before and after the intervention period. In order to match the initial diet of the groups, participants were required to follow an isocaloric diet for two weeks before the trial, and a low-calorie diet for 6 weeks during the intervention period. RESULTS: We observed a significant time dependent improvement in the systolic blood pressure measurements in the abdominal intervention group, although this improvement was more pronounce in the first period of study. Of note, in the auricular intervention group, a significant increasing in the level of SBP was detected. Importantly no statistically significant changes were found in the corresponding sham groups. CONCLUSIONS: Our findings demonstrated that abdominal electro-acupuncture for 6 weeks reduced both systolic and diastolic blood pressure and auricular acupuncture had a short-term adverse effect on both SBP and DBP.

Red electroluminescence of ruthenium sensitizer functionalized by sulfonate anchoring groups.

We have synthesized five novel Ru(ii) phenanthroline complexes with an additional aryl sulfonate ligating substituent at the 5-position [Ru(L)(bpy)2](BF4)2 (1), [Ru(L)(bpy)(SCN)2] (2), [Ru(L)3](BF4)2 (3), [Ru(L)2(bpy)](BF4)2 (4) and [Ru(L)(BPhen)(SCN)2] (5) (where L = 6-one-[1,10]phenanthroline-5-ylamino)-3-hydroxynaphthalene 1-sulfonic, bpy = 2,2'-bipyridine, BPhen = 4,7-diphenyl-1,10-phenanthroline), as both photosensitizers for oxide semiconductor solar cells (DSSCs) and light emitting diodes (LEDs). The absorption and emission maxima of these complexes red shifted upon extending the conjugation of the phenanthroline ligand. Ru phenanthroline complexes exhibit broad metal to ligand charge transfer-centered electroluminescence (EL) with a maximum near 580 nm. Our results indicated that a particular structure (2) can be considered as both DSSC and OLED devices. The efficiency of the LED performance can be tuned by using a range of ligands. Device (2) has a luminance of 550 cd m(-2) and maximum efficiency of 0.9 cd A(-1) at 18 V, which are the highest values among the five devices. The turn-on voltage of this device is approximately 5 V. The role of auxiliary ligands in the photophysical properties of Ru complexes was investigated by DFT calculation. We have also studied photovoltaic properties of dye-sensitized nanocrystalline semiconductor solar cells based on Ru phenanthroline complexes and an iodine redox electrolyte. A solar energy to electricity conversion efficiency (η) of 0.67% was obtained for Ru complex (2) under standard AM 1.5 irradiation with a short-circuit photocurrent density (Jsc) of 2.46 mA cm(-2), an open-circuit photovoltage (Voc) of 0.6 V, and a fill factor (ff) of 40%, which are all among the highest values for ruthenium sulfonated anchoring groups reported so far. Monochromatic incident photon to current conversion efficiency was 23% at 475 nm. Photovoltaic studies clearly indicated dyes with two SCN substituents yielded a higher Jsc for the cell than dyes with a tris-homoleptic anchor substituent.

Auricular or body acupuncture: which one is more effective in reducing abdominal fat mass in Iranian men with obesity: a randomized clinical trial.

BACKGROUND: The prevalence of abdominal obesity is on the rise worldwide. Previous studies have indicated the higher diagnostic value of body fat distribution pattern compared with general body in abdominal obesity assessments. Several non-pharmacological methods have been suggested for obesity management, of which acupuncture has gained a great deal of research interest with promising results. This study aimed to comparatively evaluate the effects of conventional auricular and body electroacupuncture on abdominal fat mass in obese men. METHODS: The volunteers were randomly divided into four groups, including 2 interventions and 2 controls. This study was conducted on 80 obese volunteer men with Body Mass Index (BMI) range of 30-40 kg/m2.The intervention groups including real body electroacupuncture (A), real auricular acupuncture (C) and the control groups containing sham body electroacupuncture (B), and sham auricular acupuncture (D). All groups were in combination with a low-calorie diet for 6 weeks. BMI, Trunk Fat Mass (TFM), Waist Circumference (WC), and Hip Circumference (HC) were measured pre- and post-intervention. RESULTS: In group A, respectively a significant reduction was shown in BMI (P < 0.005), TFM (P < 0.005), WC (P < 0.05, P < 0.005) and HC (P < 0.005) when compared with controls (Groups B and D). Interestingly, group C had significant decreases in BMI (P < 0.005), TFM (P < 0.01, P < 0.005), WC (P < 0.005) and HC (P < 0.001) after comparison with the sham. Likewise, WC (P < 0.05) and HC (P < 0.05) were significantly reduced post- intervention when compared with two treatment groups. CONCLUSIONS: In our study, acupuncture treatment (body or auricular) seemed to have an effect on reducing BMI, TFM, WC and HC. Comparison of the two types of treatment (body and auricular acupuncture) suggests that the two types of acupuncture had similar effects on reducing BMI and TFM, but body electroacupuncture is more effective in reducing WC and auricular in HC. It seems that both auricular and body electro-acupuncture combined with a low-calorie diet are efficient, simple and painless methods to reduce respectively the HC and WC fat in obese men, compared with conventional techniques. TRIAL REGISTRATION: IRCT201201127117N2.

Effects of auricular acupressure combined with low-calorie diet on the leptin hormone in obese and overweight Iranian individuals.

BACKGROUND: Human leptin is a peptide hormone that is released from white adipocytes. The absence of leptin or its receptor leads to uncontrolled food intake, leading to obesity. In the present work, the effects of auricular acupressure combined with low-calorie diet on the leptin hormone level were investigated. METHODS: Volunteers (n=86) with body mass indices (BMI) between 25 and 45 kg/m² were randomised into a case (n=43) or a control (n=43) group. Participants in each group received a low-calorie diet for 6 weeks. The case group was treated with auricular acupressure and the control group received a sham procedure. Plasma leptin levels, body fat mass, body weight and BMI were measured before and after treatment. RESULTS: Participants who received auricular acupressure showed significant reductions in their plasma leptin levels (18.57%, p<0.01) as well as in their body fat mass (4%, p<0.05). These changes were not observed in the control group. The reduction in leptin was significantly greater in the acupressure group than the controls. CONCLUSIONS: Auricular acupressure combined with a low-calorie diet significantly reduced plasma levels of leptin. However, the mechanism of this reduction is not clear.