1,1'-Bis-(diphenylphosphino)ferrocene appended d8- and d10-configuration based thiosquarates: the molecular and electronic configurational insights into their sensitization and co-sensitization properties for dye sensitized solar cells

Three new d8- and d10-configuration based 1,1'-bis-(diphenylphosphino)ferrocene (dppf) appended thiosquarates complexes with general composition [M(mtsq)2dppf] (M = Ni2+ (NiL2); Zn2+ (ZnL2) and Cd2+ (CdL2)) (mtsq = 3-ethoxycyclobutenedione-4-thiolate) have been synthesized and characterized spectroscopically as well as in case of NiL2 by single crystal X-ray diffraction technique. The single crystal X-ray analysis reveals square planar geometry around Ni(II) in NiL2, where Ni(II) coordinates with two sulfur centres of two mtsq ligands in monodentate fashion and two phosphorus of a dppf ligand in chelating mode. The supramolecular architecture of NiL2 is sustained by intermolecular C-H⋯O interactions to form one-dimensional chain. Further, the application of these newly synthesized complexes as sensitizers and co-sensitizers/co-absorbents with ruthenium based N719 sensitizer in dye-sensitized solar cells (DSSCs) have been explored. The DSSC set-up based on NiL2 offers best photovoltaic performance with photovoltaic efficiency (η) 5.12%, short-circuit current (Jsc) 11.60 mA cm-2, open circuit potential (Voc) 0.690 V and incident photon to current conversion efficiency (IPCE) 63%. In co-sensitized DSSC set-up, ZnL2 along with state-of-the-art N719 dye displays best photovoltaic performance with η 6.65%, Jsc 14.47 mA cm-2, Voc 0.729 V and IPCE 69%, thereby showing an improvement by 15.25% in photovoltaic efficiency in comparison to the photovoltaic efficiency of N719 sensitized DSSC set-up. Variation in co-sensitization behaviour have been ascribed to the differences in the excited state energy level of co-sensitizers. The ZnL2 and CdL2 have a higher energy level position than N719 dye, allowing efficient electron transfer to N719 during light irradiation, while excited state of NiL2 is lower than N719 dye, preventing photoexcited electron transfer to N719, resulting in its lowest overall efficiency among the three co-sensitized DSSC setups.

Alkaline hydrolysis of spent aromatic biomass for production of phenolic aldehydes, lignin, and cellulose

In order to combat the environmental issues associated with the burning of spent aromatic biomass (SAB), a method for alkaline hydrolysis of SAB has been developed to afford phenolic acids, predominantly the p-coumaric acid, lignin, and cellulose. Lignin (∼15 wt%) from alkaline hydrolysate was separated by precipitation while a mixture of phenolic acids obtained was directly reacted with a green reagent, PhI(OAc)2, under one-pot condition to afford a mixture of p-hydroxybenzaldehyde (>90 wt%) and vanillin (<10 wt%). Unreacted biomass obtained in the process was successfully used as a substrate for the production of cellulose (∼40 wt%). The developed method exhibits potential for application on an industrial scale.

New 5,5-(1,4-Phenylenebis(methyleneoxy)diisophthalic Acid Appended Zn(II) and Cd(II) MOFs as Potent Photocatalysts for Nitrophenols

Metal-organic frameworks (MOFs) are peculiar multimodal materials that find photocatalytic applications for the decomposition of lethal molecules present in the wastewater. In this investigation, two new d10-configuration-based MOFs, [Zn2(L)(H2O)(bbi)] (1) and [Cd2(L)(bbi)] (2) (5,5-(1,4-phenylenebis(methyleneoxy)diisophthalic acid (H2L) and 1,1'-(1,4-butanediyl)bis(imidazole) (bbi)), have been synthesized and characterized. The MOF 1 displayed a (4,6)-connected (3.43.52)(32.44.52.66.7) network topology, while 2 had a (3,10)-connected network with a Schläfli symbol of (410.511.622.72)(43)2. These MOFs have been employed as photocatalysts to photodegrade nitrophenolic compounds, especially p-nitrophenol (PNP). The photocatalysis studies reveal that 1 displayed relatively better photocatalytic performance than 2. Further, the photocatalytic efficacy of 1 has been assessed by altering the initial PNP concentration and photocatalyst dosage, which suggest that at 80 ppm PNP concentration and at its 50 mg concentration the MOF 1 can photo-decompose around 90.01% of PNP in 50 min. Further, radical scavenging experiments reveal that holes present over 1 and ·OH radicals collectively catalyze the photodecomposition of PNP. In addition, utilizing density of states (DOS) calculations and Hirshfeld surface analyses, a plausible photocatalysis mechanism for nitrophenol degradation has been postulated.

The role of dexmedetomidine in post cranioplasty refractory status epilepticus

Cranioplasty, specifically a repair of the skull defect resulting from a previous decompressive craniectomy, is a relatively simple procedure associated with a minimal rate of complications. Even though seizures are seen in up to 30% of the patients postoperatively, status epilepticus is not commonly described. Cerebral oedema, ischaemia and neuro-inflammation have been reported as putative causes of seizures in this population. Here, we report a case of refractory status epilepticus unresponsive to standard anti-epileptic and anaesthetic agents. The use of dexmedetomidine helped terminate the episode and led to a favourable outcome. Most of the standard anti-epileptic and anaesthetic agents act through potentiation of GABAergic transmission or sodium channel blockade and postsynaptic adrenoceptor activation by dexmedetomidine may help potentiate their effect. Further studies are needed to investigate its anticonvulsant effect on post-traumatic brain injury and elaborate on optimal dosage.

Copper(ii) and cobalt(iii) Schiff base complexes with hydroxy anchors as sensitizers in dye-sensitized solar cells (DSSCs)

Two Schiff base complexes of copper(ii) and cobalt(iii) having the formulae [CuL₂] (Cu-Sal) and [CoL₃] (Co-Sal) (HL = 2-(((2-hydroxyethyl)imino)methyl)phenol) have been synthesized and characterized microanalytically, spectroscopically and in the case of Cu-Sal using single crystal X-ray diffraction technique. The single crystal X-ray analysis reveals a square planar geometry around Cu(ii) satisfied by phenoxide oxygen and imine nitrogen of the L^- ligand to generate a six membered chelate ring. The solid state structure of Cu-Sal is satisfied by varied intermolecular non-covalent interactions. The nature of these interactions has been addressed with the aid of Hirshfeld surface analysis. Both compounds have been used as sensitizers in TiO₂ based dye sensitized solar cells (DSSCs) and the DSSC experiments revealed that Co-Sal offers better photovoltaic performance in comparison to Cu-Sal. The Co-Sal exhibited a J _sc of 9.75 mA cm^-2 with a V _oc of -0.648 V, incident photon to current conversion efficiency (IPCE) of 57% and η of 3.84%. The relatively better photovoltaic performance of Co-Sal could be attributed to better light absorption and dye loading than that of Cu-Sal.

New Heteroleptic 1,2-Bis(diphenylphosphino)ethane Appended Cobalt(III) Ferrocene Dithiocarbamates as Sensitizers in Dye Sensitizer Solar Cells (DSSCs)

Three new heteroleptic 1,2-bis(diphenylphosphino)ethane (dppe) appended Co(III) ferrocene dithiocarbamate complexes with formula [Co(dppe)(Fcdtc)]PF6 ((Fcdtc = N-benzyl-N-methylferrocene dithiocarbamate (Co-FcBz), N-2-methylpyridyl-N-methylferrocene dithiocarbamate (Co-FcPy) and N-ethanol-N-methylferrocene dithiocarbamate (Co-FcEtOH); dppe = 1,2-Bis(diphenylphosphino)ethane) have been...

A double co-sensitization strategy using heteroleptic transition metal ferrocenyl dithiocarbamate phenanthrolene-dione for enhancing the performance of N719-based DSSCs

Three new heteroleptic dithiocarbamate complexes with formula [M(Phen-dione)(Fcdtc)]PF₆ (where M = Ni(ii) Ni-Fc, Cu(ii) Cu-Fc) and [Co(Phen-dione)(Fcdtc)₂]PF₆ (Co-Fc) (Fcdtc = N-ethanol-N-methylferrocene dithiocarbamate and Phen-dione = 1,10-phenanthroline-5,6-dione; PF₆ ^- = hexafluorophosphate) were synthesized and characterized using microanalysis, FTIR, electronic absorption spectroscopy and mass spectrometry. The solution state electronic absorption spectroscopy for all three complexes displayed a band at ∼430 nm corresponding to the ferrocene unit and another low-intensity band in the visible region arising because of the d-d transitions. These newly synthesized complexes were used as co-sensitizers for the state-of-the-art di-tetrabutylammonium cis-bis(isothiocyanato)bis(2,2'-bipyridyl-4,4'-dicarboxylato)ruthenium(ii) (N719) dye in dye-sensitized solar cells (DSSCs). Among the three co-sensitizers/co-adsorbent-based DSSC set-ups, the assembly fabricated using Co-Fc/N719 displayed good photovoltaic performance with 5.31% efficiency (η) while a new triple component strategy inculcating N719, Co-Fc and Cu-Fc dyes offered the best photovoltaic performance with 6.05% efficiency (η) with incident photon to current conversion efficiency (IPCE) of 63%. This indicated an upliftment of the DSSC performance by ∼38% in comparison to the set-up constructed by employing only N719 dye (η = 4.39%) under similar experimental conditions.

Phase-controlled solvothermal syntheses and oxygen evolution reaction (OER) activity of nickel sulfide nanoparticles obtained from 1,2-bis(diphenylphosphino)ethane nickel(II) acetylacetonatedithiolate

A new heteroleptic nickel(II) complex [Ni(dppe)(acac)].CHCl3 (1) (where acac = acetylacetonatedithiolate, dppe =1,2-bis(diphenylphosphino)ethane) has been synthesized and characterized by different spectroscopic techniques and single-crystal X-ray diffraction. The solvothermal decomposition of...

Ocular trauma in counter insurgency and proxy war environment: Epidemiological study, 1992-2004

Background

To analyze the epidemiology of hospitalized ocular injuries occurring in counter insurgency and proxy war environment in a forward area of northern India over a period of 13 years.

Methods

Retrospective observational study of medical records was performed of 458 patients with ocular injuries primarily treated at zonal referral hospital of Indian Army between January 1992 and December 2004.

Results

A total of 559 eyes with ocular injuries were studied. The average age of the victims was 30 years. In 77% cases, injuries were sustained by army personnel and remaining by paramilitary forces. Of all cases, 86.5% cases were due to combat-related (militant action), of which 93.9% cases were caused by splinters from munitions. Among the eyes injured due to militant action, 60.36% were open globe injuries, 31.19% were closed globe injuries and 8.45% were isolated adnexal injuries. Among the eyes injured, 76.33% of the eyes with open globe injuries owing to militant action had perforating injuries, whereas in closed globe injuries, 47.74% eyes had corneal foreign body. Among eyes with open globe injuries, Corneo-scleral, scleral and corneal lacerations were seen in 45%, 28% and 27% eyes respectively. 15.75% of eyes with ocular injuries underwent eviscerations.

Conclusion

The study reveals that splinter eye injuries from munitions were the most common cause of ocular morbidity in counter insurgency and proxy war. Implementation of use of protective glasses by the personnel deployed in such hostile environment and strict compliance of preventive measures would be effective in saving eyes and also medical and economic resources.

Multivariate analysis of adaptive response to ferulic acid and p-coumaric acid after physiological stresses in Cronobacter sakazakii

AIM

The present study demonstrated the antimicrobial activity of ferulic acid and p-coumaric acid against unstressed and stressed (cold stressed, starved and desiccated) Cronobacter sakazakii in laboratory media (37°C) and reconstituted powdered infant formulation (PIF) with mild heat treatment (50°C).

METHODS AND RESULTS

Five phenolics, namely, quercetin, rutin, caffeic acid, ferulic acid and p-coumaric acid, were tested for antimicrobial activities against five strains of C. sakazakii either unstressed or stressed. Strain specific higher resistance to ferulic acid and p-coumaric acid was observed after stress adaptation in laboratory media. The effect of cross protection was validated using reconstituted PIF as delivery vehicle of selected compounds. Both p-coumaric acid and ferulic acid showed inhibition of C. sakazakii in a dose and time dependent manner as revealed by their viable cell counts. Principal component analysis revealed that the desiccated cells were more sensitive to phenolics in reconstituted PIF.

CONCLUSIONS

Only ferulic acid and p-coumaric acid showed marked antibacterial activity with minimum inhibitory concentration in the range of 2·5-5 mg ml^-1 for unstressed C. sakazakii cells in tryptone soy broth. The maximum inhibition was achieved with 20 mg ml^-1 of both the tested polyphenols in reconstituted PIF. Cold stress and starvation stress did not impart any protection nor increased the susceptibility of C. sakazakii, whereas desiccation resulted in increased susceptibility to phenolic compounds.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results obtained in this study helps in understanding the effect of environmental stresses during processing on susceptibility of C. sakazakii to natural antimicrobial agents. Future transcriptomic studies and functional genetic studies are warranted to understand the strain specific stress responses for the development of better control methods possibly by using these natural antagonists.

Activation of the receptor tyrosine kinase RET improves long-term hematopoietic stem cell outgrowth and potency

Expansion of human hematopoietic stem cells (HSCs) is a rapidly advancing field showing great promise for clinical applications. Recent evidence has implicated the nervous system and glial family ligands (GFLs) as potential drivers of hematopoietic survival and self-renewal in the bone marrow niche; how to apply this process to HSC maintenance and expansion has yet to be explored. We show a role for the GFL receptor, RET, at the cell surface of HSCs in mediating sustained cellular growth, resistance to stress, and improved cell survival throughout in vitro expansion. HSCs treated with the key RET ligand/coreceptor complex, glial-derived neurotrophic factor and its coreceptor, exhibit improved progenitor function at primary transplantation and improved long-term HSC function at secondary transplantation. Finally, we show that RET drives a multifaceted intracellular signaling pathway, including key signaling intermediates protein kinase B, extracellular signal-regulated kinase 1/2, NF-κB, and p53, responsible for a wide range of cellular and genetic responses that improve cell growth and survival under culture conditions.

Measurement of neutron induced 86Sr(n, 2n)85Sr reaction cross sections at different neutron energies

The cross-sections for ⁸⁶Sr (n, 2n)⁸⁵Sr reaction are measured at neutron energies 19.44 ± 1.02 MeV and 16.81 ± 0.85 MeV wherein there is scarcity of data. The standard neutron activation analysis technique and offline gamma ray spectroscopy have been employed for measurement and analysis of the data. The results are compared with experimental data available in EXFOR database, JEFF-3.3, JENDL-4.0, TENDL-2017 and ENDF/B-VIII.0 evaluated data. The theoretical prediction was incorporated using nuclear modular codes TALYS 1.8 and EMPIRE 3.2.2. A detailed comparative study of experimental results with the theoretical models and various major evaluations has been presented.

Ferrocenylethenyl-substituted oxadiazoles with phenolic and nitro anchors as sensitizers in dye sensitized solar cells

Ferrocenylethenyl-substituted oxadiazoles with phenolic and nitro anchors were synthesized and used as sensitizers in dye sensitized solar cells (DSSCs).

Survival and prognostic factors for glioblastoma multiforme: Retrospective single-institutional study

INTRODUCTION

Glioblastoma multiforme (GBM) is the most common and aggressive primary brain tumor in adults. The standard management has been maximum surgical resection followed by adjuvant radiotherapy with concurrent chemotherapy followed by adjuvant chemotherapy. Although the survival rate of patients with GBM has improved with recent advancements in treatment, the prognosis remains generally poor. The median survival rates are in the range of 9-12 months and 2-year survival rates are in the range of 8%-12%.

MATERIALS AND METHODS

A single-institution retrospective review of 61 patients of GBM from 2012 to 2014. Data regarding patient factors, disease factors, and treatment factors were collected and survival has been calculated.

RESULTS

A total of 61 patients with GBM were analyzed. GBM is commonly seen in sixth decade of life. Male to female ratio is 2.6:1. The right side of the brain is commonly involved with right frontal lobe being the most common site. The median follow-up was 4.6 months. The median survival of our patients was 8 months. The 1-year and 2-year survival rates were 20% and 3.27%, respectively.

CONCLUSIONS

The overall survival and prognosis in patients with GBM remains poor despite of constant research and studies. Concurrent chemoradiotherapy followed by adjuvant chemotherapy with temozolomide should be used after maximal resection to improve the survival.

1,1′-Bis(diphenylphosphino)ferrocene-appended nickel(ii) dithiolates as sensitizers in dye-sensitized solar cells

Herein, two dppf-appended Ni(ii) dithiolates with 2,2-diacetyl and 2-nitro anchors were prepared, and their light harvesting properties were explored in dye-sensitized solar cells (DSSCs).

Ferrocenyl benzimidazole with carboxylic and nitro anchors as potential sensitizers in dye-sensitized solar cells

Two ferrocenyl benzimidazoles with carboxylic and nitro anchors were prepared and their light harvesting properties explored in dye-sensitized solar cells (DSSCs).

1,2-Bis(diphenylphosphino)ethane nickel(ii) O,O′-dialkyldithiophosphates as potential precursors for nickel sulfides

Three new dppe nickel(ii) dithiophosphates with different counteranions synthesized and decomposed to obtain Ni–S systems with same phase independent of the nature of counteranions and alkyl fragments.

Successful Renal Transplantation Across HLA Barrier: Report from India

Organ donors are sometimes found “unsuitable” due to the presence of donor-specific anti-HLA antibodies in the recipient. In recent years, improved desensitization protocols have successfully helped to overcome HLA incompatibility hurdle. We present three cases where optimum desensitization was achieved in patients with the donor-specific anti-HLA antibody (DSA) leading to successful renal transplantation. All patient–donor pair underwent HLA typing, complement dependent cytotoxicity crossmatch (CDC-XM), flow cytometry XM (FC-XM), and panel reactive antibody. If any of the three tests was positive, single antigen bead assay was performed to determine the specificity of the anti-HLA antibody (s). Patients with DSA were offered organ-swap or anti-HLA antibody desensitization followed by transplantation. Desensitization protocol consisted of single dose rituximab and cascade plasmapheresis (CP) along with standard triple immunosuppression. The target DSA mean fluorescence index (MFI) was <500, along with negative CDC-XM and FC-XM for both T- and B-cells. Three patients with anti-HLA DSA, who did not find a suitable match in organ swap program, consented to anti-HLA antibody desensitization, followed by transplantation. Mean pre-desensitization antibody MFI was 1740 (1422–2280). Mean number of CP required to achieve the target MFI was 2.3 (2–3). All the three patients are on regular follow-up and have normal renal function test at a mean follow-up of 8 months. This report underlines successful application of desensitization protocol leading to successful HLA-antibody incompatible renal transplants and their continued normal renal functions.

The Learning Curve of Pure Retroperitoneoscopic Donor Nephrectomy

BACKGROUND

Retroperitoneoscopic donor nephrectomy (RDN) is a well-established modality for the procurement of kidneys for renal transplantation. However the learning curve of pure RDN is not yet defined. Defining the learning curve will help in proper mentorship of the new donor surgeons besides providing safety to the donors.

OBJECTIVE

To define the learning curve of pure RDN.

METHODS

We analyzed the prospectively collected data of 102 voluntary kidney donors who underwent RDN by a single surgeon between August 2012 and April 2015 at our center. The donors were classified into group A (1-34), group B (35-68), and group C (69-102) according to the chronological order of their surgery. Left RDN was performed in 28 (82%), 25 (74%), and 28 (82%) donors of group A, B, and C, respectively. Right RDN was performed in 6 (18%), 9 (26%), and 6 (18%) donors of group A, B, and C, respectively. The clinical data were analyzed for each group.

RESULTS

Statistically significant difference was observed for the mean operative time (p<0.01) and warm ischemia time (p<0.04). The operative time remained around 200 minutes after the initial 35 cases.

CONCLUSION

The learning curve of pure RDN was 35 cases, although the mastery requires more number of cases to be performed.

Supraclavicular brachial plexus block using ropivacaine alone or combined with dexmedetomidine for upper limb surgery: A prospective, randomized, double-blinded, comparative study

BACKGROUND

Dexmedetomidine is a new α-2 receptor agonist with analgesic and sedative properties. We used dexmedetomidine along with ropivacaine for supraclavicular brachial plexus block.

METHODS

Eighty ASA grade I-II patients, 18-60 years old, scheduled for elective upper limb orthopaedic surgery under supraclavicular brachial plexus block, were included in this prospective study. The patients were randomly assigned to group R (ropivacaine alone) and group RD (ropivacaine and dexmedetomidine) (40 patients in each group). Group R received ropivacaine 0.50% (30 cc)+placebo and group RD received ropivacaine 0.50% (30 cc)+dexmedetomidine 1 μg/kg. Primary outcome measure was duration of analgesia. Secondary measures were onset and duration of sensory blockade, pain scores, onset and duration of motor blockade, and evidence of any adverse drug reactions.

RESULTS

There was no significant difference hemodynamic parameter during intra-operative period. Group RD showed a statistically significant shorter time to onset of sensory blockade (10.75±2.71 vs. 16.75±2.96 min, P=.003), longer sensory block duration (379.40±55.09 vs. 211.60±47.88 min, P=.002), shorter onset time to motor blockade (14.35±2.58 vs. 20.25±4.13 min, P=.003), longer motor block duration (312.0±49.91 vs. 184.7±36.76 min, P=.002), longer duration of postoperative analgesia (413.73±89.92 vs. 197.35±28.67 min, P=.002). Three patients in the group RD developed somnolence. (P=.04).

CONCLUSION

Dexmedetomidine along with ropivacaine decreases the onset of motor and sensory block and increases the duration of sensory and motor block in supraclavicular brachial plexus block.

Ferrocenyl chalcones with phenolic and pyridyl anchors as potential sensitizers in dye-sensitized solar cells

Five ferrocenyl chalcones with phenolic and pyridyl anchors were prepared and their light harvesting properties explored in dye-sensitized solar cells (DSSCs).

Adequacy of twice weekly hemodialysis in end stage renal disease patients at a tertiary care dialysis centre

Hemodialysis has improved the morbidity and mortality associated with end stage renal disease. In India, hemodialysis prescription is empiric, which leads to complications related to under-dialysis. Hence, adequacy of hemodialysis in Indian setting was analyzed in this study. A total of 50 patients on twice per week hemodialysis were assessed for 1 month. The number of sessions meeting standards laid out by Kidney Diseases Outcome Quality Initiatives (KDOQI) guidelines were calculated. They were divided into two groups: one in whom dialysis was monitored and session length enhanced to meet the minimum standard Kt/V of 2 and second control group; where Kt/V was not monitored. Hemoglobin (Hb) levels, albumin levels, mean arterial pressure and World Health Organization (WHO) quality of life (QoL) score were compared in the two groups after 6 months. Only 28% of hemodialysis sessions were adequate as per KDOQI guidelines. There was significant improvement in Hb levels (1.47 vs. 0.15 g/dl), mean arterial pressure levels (15.2 vs. 3.16 mm Hg), serum albumin levels (0.82 vs. 0.11 g/dl) and WHO QoL score (17.2 vs. 2.24) in study group as compared to control group. Standard Kt/V can be used as an important tool to modify twice weekly dialysis sessions to provide better QoL to the patients. However, studies with larger sample size are required to conclusively prove our results.

Synthesis, characterization and light harvesting properties of Sb(III) and Bi(III) ferrocenyl dithiocarbamate complexes

New Sb(III) and Bi(III) ferrocenyl dithiocarbamate complexes viz. [Sb(FcCH2Bzdtc)3] (Sb) and [Bi(FcCH2Bzdtc)3] (Bi) (Fc=C5H5FeC5H4-; Bz=C6H5CH2-) have been synthesized and characterized by elemental analyses, IR, (1)H and (13)C NMR spectroscopies. The optical, electrochemical and photovoltaic properties of the synthesized complexes were investigated. The light harvesting properties of both of the compounds have been studied using these compounds as photosensitizers in TiO2-based DSSCs. The photovoltaic devices fabricated by Sb and Bi showed a maximum current conversion efficiency of 1.51% and 0.97%, respectively under 1.5 AM illumination (100 mW cm(-2)) and having incident photon to current efficiency (IPCE) of 38% and 31%, respectively. The reason for the higher efficiency of Sb is due its higher dye loading.

A vapor phase adsorptive desulfurization process for producing ultra low sulphur diesel using NiY zeolite as a regenerable adsorbent

A NiY zeolite based vapor phase adsorptive desulfurization process has been described which can bring down sulphur concentration of a commercial BS IV grade (Euro IV equivalent) diesel from 50 ppm to a <5 ppm level.