Entropy-driven nonequilibrium phonon-stimulated electron-phonon coupling in tin dioxide nanorods

Nonequilibrium (NEQ) phonon fluctuation in a nanosystem has been studied through the statistical assessment of the entropy-production and -consumption events in ultrasmall tin dioxide (SnO_{2}) nanorods. Size- and shape-dependent alteration in free energy leading to modulation of the probability distribution function of the phonon dynamics has been observed from the x-ray diffraction and Raman scattering characterizations. The Gallavotti-Cohen nonequilibrium fluctuation theorem has been utilized to qualitatively describe the aforementioned behaviors under the influence of a global flux. The observation of entropy consumption and thermodynamically favorable entropy-production events indicates the presence of NEQ fluctuations in the phonon modes. The effective energy scale of fluctuation in driven phonon modes, dissipating energy faster than relaxation time, is quantified on the order of nanojoules. From optical absorption and photoluminescence studies, the observation of the electron-phonon coupled state confirms the interaction of the NEQ phonons with electrons. The strength of the coupling has been estimated from the temperature-independent Barry center shift and found to be enhanced to 5.35. Valence band x-ray photoelectron spectroscopy and Fourier transformed infrared spectroscopy analyses reconcile NEQ phonon mediated alteration of the valence band density of states, activation of silent phonon modes, and superior excitonic transitions, suitable for the new generation of ultrafast quantum device applications.

Observation of non-equilibrium fluctuation in the shear-stress-driven hemoglobin aggregates

Non-equilibrium fluctuations caused by the rearrangement of hemoglobin molecules into an aggregate state under shear stress have been investigated experimentally. The flow response under the shear stress (σ) corroborates the presence of contrasting aggregate and rejuvenation states governed by entropy production and consumption events. From the time-dependent shear rate fluctuation studies of aggregate states, the probability distribution function (PDF) of the rate of work done is observed to be spread from negative to positive values with a net positive mean. The PDFs follow the steady-state fluctuation theorem, even at a smaller timescale than that desired by the theorem. The behavior of the effective temperature (Teff) that emerges from a non-equilibrium fluctuation and interconnects with the structural restrictions of the aggregate state of our driven system is observed to be within the boundary of the thermodynamic uncertainty. The increase in Teff with the applied σ illustrates a phenomenal nonlinear power flux-dependent aggregating behavior in a classic bio-molecular-driven system.

Correlation of Dose Volume Parameters with Dysphagia and Pharyngeal Constrictor Muscle Thickness in Dysphagia Optimized IMRT

PURPOSE/OBJECTIVE(S)

Reduced radiation dose to the pharyngeal constrictor muscles (PCM) using dysphagia optimized intensity-modulated RT (DO-IMRT) is associated with improved swallowing outcomes in oropharyngeal cancers (OPCs). Purpose was to evaluate the relationship between dose of radiation delivered and acute dysphagia in patients with OPC treated with IMRT, after delineation of PCM.

MATERIALS/METHODS

Twenty-five patients with newly diagnosed OPC who underwent definitive IMRT with concurrent cisplatin were included in the study. PCM mean dose < 50 Gy was used as the dose constraint. Target volume was divided into high, intermediate and low risk areas receiving doses in the range of 60-66 Gy, 54-58 Gy, 51-56 Gy in 30-33 fractions over 6-6.5 weeks, respectively. PCM dose-volume parameters were collected and logistic regression was used to analyze these data relative to percent weight loss during RT and duration of feeding tube use. Thickness of constrictor muscle in pre-treatment and 3 months post-therapy CT scan were assessed. Weekly assessment of dysphagia was based on RTOG toxicity gradings. Aim of the study was to evaluate the correlation between dysphagia grades with dose-volume parameters and PCM thickness.

RESULTS

Median age was 55.0 years (mean 54.3) with 24 males and stage II:III-16:9 patients. Dmean to PCM was 49.86 Gy (range 48.22 -57.63) with median Dmax of 70.24 Gy. For patients with dysphagia (grade ≥1), V50 ranged from 48.2-57.23%, while in those with no dysphagia, it ranged from 47.92-52.18 % (Mean 51.36%). Nine patients needed feeding tube after RT end. Median feeding tube duration was 64 days. The correlation between Dmean ≥ 50 Gy and dysphagia at 1st, 2nd, 3rd and 6th month was found statistically significant (p < 0.01). Table 1 shows the Pearson correlation and P-value of the dosimetric parameters with dysphagia. The correlation of V50 was found statistically significant with grade of dysphagia at 3rd and 6th month post-treatment (p<0.001). The mean thickness range and median thickness of constrictors before and 3 months after treatment were 1.8-3.2 mm, 2.4 mm, and 2.8-6.2 mm,4.1 mm, respectively. The increase in thickness of constrictor muscle correlated significantly (p<0.05) with dysphagia grades and also with V50, V60 and Dmean (p<0.001) but no statistical significance was seen with Dmax (p = 0.232). With a median follow-up of 18 months (range 7-24), 1-year actuarial local control was 92%.

CONCLUSION

DO-IMRT may prove beneficial in the OPC by preventing dysphagia and aspiration post therapy and hence improving the quality of life of patients. Dmean ≥ 50Gy, V50 > 51.4% and V60 > 35.5% are the parameters correlating significantly with dysphagia (p<0.001) and change in mean thickness of PCM (p<0.001).

Analyzing the impact of close margins and extra-resection margins on failure rates in postoperative oral cavity cancers

BACKGROUND

Postoperative oral cancers with close margins belong to medium- to high-risk category for local failure. During re-surgery for close margins, there is sufficient doubt as to whether the re-excised tissue is from the same region as the close margin. Therefore, we planned a retrospective review of these cases of close margins that were re-excised with extra-resection margins (ERMs).

MATERIAL AND METHODS

Details of 2011 oral cavity patients resected at our hospital were retrieved. Cases with close margins were segregated and the status of ERMs was noted. The postoperative histopathological details, radiotherapy details, and failure patterns in all these cases were documented. The primary objective of the study was to assess the overall survival (OS) and disease-free survival (DFS) in cases with ERMs. The secondary objective was to assess the local and regional control rates and variation with the number and status of close and ERMs. OS, DFS, and local failure rates were defined from the date of registration. Statistical analysis was performed with the SPSS statistical software package. All survival analyses were performed using the Kaplan-Meier method. Log-rank test was used to test the statistical significance. A P-value of 0.05 was considered statistically significant.

RESULTS

Sixty-four cases with a median age of 47 years (range: 29-76) were considered for the final analysis. The median follow-up was 40 months (range: 9.5-56.5). The 2-year OS and DFS rates were 91.5% and 88.5%, respectively. The crude local and regional failure rates were 10.9% and 3.1%, respectively. The 3-year locoregional control rate was 90.2%. The 2-year locoregional control rate for one close margin was significantly better as compared to more than one close margin (P = 0.049). No difference in survival and failure rates was found between the number of ERMs resected (one vs. two) and ≤ vs. > 3 mm close margin status. Two patients developed bone metastases.

CONCLUSION

The survival rates and locoregional control rates did not differ much between the groups that had one or more ERMs. However, the locoregional control rates were better in cases with one close margin as compared to those with more than one close margin. A larger study with longer follow-up is needed to detect statistically significant differences in outcomes and identify the factors that portend poor prognosis in these cases with close margins and ERMs.

222 TOWARDS A DELIRIUM FRIENDLY EMERGENCY DEPARTMENT

Background

Delirium affects approx. 10-30 % of patients over the age of 65. Up to 70% of cases are missed in the Emergency Department (ED). Delirium results in increased morbidity, mortality, increased length of stay and decreased functional status with increased discharges to residential care centres. Delirium in the ED is an independent predictor of death within 6 months.

Methods

We completed an audit which showed 40% of those &gt; 65 years of age in the ED were delirious and 60% of those had dementia. None of these had been identified as delirious prior to review. We have approx. 5,000 patients &gt;75 years of age attending our ED annually (1/7th of presentations). This audit was used as a catalyst for our quality improvement project. We established a steering group with a small quality improvement sub-committee. We combed the literature, identified areas for improvement and costed our project. We also looked at reliance on 1:1 carers for those with delirium and potential benefits to patient, staff and management.

Results

We used the SPARK ignite programme as a means to gain momentum and also educate ourselves on business management and change management. We competed in the finals with our “delirium package” – focussing on orientation, stimulation, safety and education. These 4 pillars of delirium care have been shown to prevent delirium, reduce hospital stay for those with delirium and also augment their delirium cycle. Competing and winning a prize highlighted the importance of delirium care and brought our project to a bigger stage.

Conclusion

Due to our multi-disciplinary team composed of non-consultant hospital doctors, advanced nurse practitioners and occupational therapists, we have been able to introduce the national dementia programme for early identification of delirium in the emergency department. We now have a space for managing those with delirium and have received funding to put our package in place. This can be replicated in hospitals around the country highlighting the non-pharmacological treatments for delirium.

Maintenance therapy with a poly(ADP-ribose) polymerase inhibitor in patients with newly diagnosed advanced epithelial ovarian cancer: individual patient data and trial-level meta-analysis

Background

We synthesize the efficacy and toxicity of poly(ADP-ribose) polymerase inhibitors (PARPis) in patients with newly diagnosed advanced ovarian cancer.

Patients and methods

We manually extracted individual patient data (IPD) for progression-free survival (PFS) from published survival curves of randomized controlled trials (RCTs) that compared PARPi versus placebo as maintenance therapy in first-line treatment, for whole study populations and subgroups, based on BRCA1/BRCA2 mutation (germline and/or somatic) and homologous recombination deficiency (HRD) status, using WebPlotDigitizer software. The respective PFS curves for each study and combined population were reconstructed from extracted IPD. The primary outcome was PFS in combined whole population and subgroups.

Results

In IPD analysis of combined population from three RCTs, with 2296 patients and 1287 events, PFS was significantly longer in PARPi versus placebo [median 20.4 (95% confidence interval (CI) 18.6-21.9) versus 14.9 (95% CI 13.9-16.5) months, respectively; hazard ratio (HR) 0.67, 95% CI 0.60-0.75; P < 0.001]. In IPD subgroup analyses from four eligible RCTs (2687 patients and 1485 events), median PFS was significantly longer in PARPi versus placebo arm, in the BRCA-mutated (45.7 versus 17.7 months, respectively; HR 0.38, 95% CI 0.32-0.46; P < 0.001), HRD-positive including BRCA-mutated (34.7 versus 17.9 months, respectively; HR 0.45, 95% CI 0.38-0.54; P < 0.001), and HRD positive excluding BRCA-mutated (22.3 versus 13.1 months, respectively; HR 0.47, 95% CI 0.34-0.65; P < 0.001) subgroups, but not in the HRD-negative (15.0 versus 11.3 months, respectively; HR 0.90, 95% CI 0.76-1.05; P = 0.75) subgroup. Results of trial-level meta-analysis were concordant with IPD analysis in whole population and subgroups.

Conclusions

Among newly diagnosed ovarian cancer patients, PARPi maintenance therapy significantly improves PFS in those with germline and/or somatic BRCA mutation and/or HRD-positive tumor but not in those with HRD-negative tumor.

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Maintenance PARPi resulted in significant PFS improvement in total population, but benefit varied in subgroups.

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PARPi showed PFS gain in BRCA-mutated (45.7 versus 17.7 m) and HRD-positive subgroups.

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No significant PFS benefit was seen in the HRD-negative subgroup (15.0 versus 11.3 months; P = 0.75).

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PARPi should be a standard treatment in newly diagnosed ovarian cancer patients except those with HRD-negative tumors.

Light Emitting Spin Active Electronic States in Ultra-Thin Mn Doped CdSe Layered Nanosheets

The layered nanosheets exhibit a variety of physical and optical properties originating from amalgamation of intra- and inter- layer electronic interactions, which makes them promising materials for advanced devices with varsatile controlling channels. In particular, the dilute magnetic semiconductor multilayered nanosheets have promising optical, electrical and magnetic properties that have been less explored so far. Here, the spin permissible optical properties from solvothermally grown Mn doped CdSe (thickness ~2.26 nm) multilayered nanosheets are reported on. The presence of multi-phase magnetic orderings with a sharp ferromagnetic transition at temperature ~48 K pertinent to the stabilization and co-existence of Mn²⁺ and Mn³⁺ based local phases have been observed from the (Cd,Mn)Se layered nanosheets corroborating to the x-ray absorption near edge structure, electron paramagnetic resonance, Raman scattering and magnetic measurements. The optical absorption and photoluminescence (PL) studies at room temperature affirm wide array of optical properties in the visible regime corresponding to the band edge and intriguing dopant-phase mediated spin approved transitions. The circularly polarized magneto-PL and life time analysis exhibits the spin-polarized fast radiative transitions confirming the presence of spin-active electronic states.

Observation of self-polarization in BSA protected Au20 clusters

Bovine serum albumin (BSA)-protected gold clusters (atomicity ∼ 20), prepared using a wet chemical route, show strong dipolar radiative transition with a gap energy of 1.93 eV due to the high oscillator strength, as confirmed by the emission studies. Self-arrangement of the clusters with fixed atomicity yields a low dispersive dielectric and electric self-polarization nature. The electrical hysteresis loop measurements returned a remanent polarization of 0.05 μC cm^-2, which can be correlated with the dipolar orientation (activation energy ∼ 45.32 meV), originating from the structure-dependent deformation of the charge density.

White-light emission by phonon assisted coherent mixing of excitons in Au8-CdS hybrid nanorods

Gold cluster (Au₈) coated CdS hybrid nanorods (HNRs), synthesized using a sonication assisted assembly route, exhibit phonon assisted coherent mixing of excitons. As observed from optical absorption, Raman scattering, x-ray diffraction and transmission electron microscopic studies, the Au₈ modulates the crystal-and electronic-structure of the CdS nanorods, effecting enhancement of exciton-phonon (e-p) interactions. The e-p interaction and entropy effect mediated phase matching of the excitonic transitions, leading-via cooperative and coherent mixing of the excitons' color-to the emission of white light, has been confirmed from room temperature and time resolved photoluminescence measurements.

CH3NH3PbI3, A Potential Solar Cell Candidate: Structural and Spectroscopic Investigations

Hybrid organic-inorganic metal halides of the type CH₃NH₃PbX₃ have emerged as potential materials for photovoltaic applications. In this paper we discuss structural, electronic, and optical spectroscopy investigations performed on high quality single crystals of CH₃NH₃PbI₃. Our results conclusively suggest that CH₃NH₃PbI₃ crystallizes in centrosymmetric space group and the methylammonium moiety exhibits disordered packing at room temperature. Extracted values of the exciton binding energy, the electron-phonon coupling constant, and the schematic energy level diagram constructed from the emission broadening, Raman, and photoemission spectroscopy measurements clearly show the potential of this system in photovoltaic applications.

Weekly cisplatin (30-40 mg/m2) as radiosensitizer: Is it high or moderate emetic agent?

PURPOSE

The American Society of Clinical Oncology (ASCO) guideline recommends a high antiemetic prophylaxis for any dose of cisplatin. This hypothesis was tested by us in this analysis of solid tumor patients who received weekly cisplatin as a radiosensitizer in a dose range of 30-40 mg/m2.

METHODS

This was a retrospective analysis of 181 solid tumor patients who received weekly cisplatin (in the dose range of 30-40 mg/m2) as a radiosensitizer between July 2015 and August 2015. The antiemetic prophylaxis schedule provided was classified as optimal (if a high antiemetic prophylaxis was provided) or suboptimal (if a nonhigh antiemetic prophylaxis was provided). The incidence of acute, delayed and breakthrough vomiting after chemotherapy was noted. SPSS version 20 was used for analysis. Fisher's exact test was used to determine the association between antiemetic schedule (suboptimal vs. optimal) and postchemotherapy emesis.

RESULTS

In the present study, of 181 patients, only 25 patients (13.8%) received optimal antiemetic prophylaxis while the remaining 156 (86.2%) received suboptimal prophylaxis. In the cohort of patients with suboptimal prophylaxis, dexamethasone was omitted in all patients (100%) while NK receptor antagonist was omitted in 76 patients (48.7%). The rate of vomiting was lower in patients receiving optimal prophylaxis as compared to that in patients receiving suboptimal prophylaxis (12% vs. 39.75%; P - 0.005).

CONCLUSION

Omission of dexamethasone followed by aprepitant was the main reason for suboptimal prophylaxis. High antiemetic prophylaxis in accordance with ASCO guidelines overall decreased the risk of emesis in patients receiving CTRT with weekly cisplatin in the dose range of 30-40 mg/m2.

[Key Points of Intraoperative Diagnostic Measures Performed by Anaesthesiologists]

The main focus of surgeons and anaesthesiologists during a surgical procedure is on safety and optimal treatment of the patient. Within the scope of interdisciplinary collaboration, the intraoperative communication between surgeons and anaesthesiologists is the basis of case-, findings- and surgery-phases-adapted patient management. The perioperative monitoring of patients and the implementation of diagnostic measures by anaesthesiologists are essential for optimal patient management. The results of the examinations may significantly determine the course of surgery. Therefore, it is important for surgeons to be familiar with the relevant intraoperative diagnostic measures.

Management of hip fractures in older people in Beijing: a retrospective audit and comparison with evidence-based guidelines and practice in the UK

Despite the high burden of hip fracture in China, there is limited information on its management. This study investigated the management of hip fractures in a Beijing tertiary hospital and compared practice with that in 180 hospitals in the UK. The findings show a significant gap exists between the countries.

INTRODUCTION

The purpose of this study was to determine if the management of older people with hip fractures in a Beijing tertiary hospital is comparable with the UK best practice guidelines for hip fracture management and the UK National Hip Fracture Database 2012, obtained from 180 hospitals.

METHODS

A retrospective audit was undertaken in a large tertiary care hospital in Beijing. Data were compared with the National Hip Fracture Database 2012 collected in 180 hospitals in the UK on the proportion of patients managed according to the UK Blue Book standards.

RESULTS

Sixty-six percent of patients were admitted to an orthopaedic ward within 24 h of fracture, while 100 % of patients in the UK were admitted to an orthopaedic ward within 24 h of arrival to an accident and emergency department. Only 8 % of patients received surgery within 48 h of admission compared with 83 % in the UK; 10 % received no surgery compared with 2.5 % in the UK; and 27 % received orthogeriatrician assessment compared with 70 % in the UK. New pressure ulcers developed in 2 % of patients compared with 3.7 % of those in the UK; whereas, 0.3 % of patients were assessed for osteoporosis treatment and 3.8 % received falls assessment, and comparable figures for the UK were 94 and 92 %, respectively.

CONCLUSIONS

Significant gaps exist in hip fracture management in the Beijing hospital compared with the best practice achieved in 180 UK hospitals, highlighting the need to implement and evaluate proactive strategies to increase the uptake of best practice hip fracture care in China.

Bayesian analysis of two diagnostic methods for paediatric ringworm infections in a teaching hospital

Quantitatively, conventional methods of diagnosis of tinea capitis or paediatric ringworm, microscopic and culture tests were evaluated with Bayes rule. This analysis would help in quantifying the pervasive errors in each diagnostic method, particularly the microscopic method, as a long-term treatment would be involved to eradicate the infection by the use of a particular antifungal chemotherapy. Secondly, the analysis of clinical data would help in obtaining digitally the fallible standard of the microscopic test method, as the culture test method is taken as gold standard. Test results of 51 paediatric patients were of 4 categories: 21 samples were true positive (both tests positive), and 13 were true negative; the rest samples comprised both 14 false positive (microscopic test positivity with culture test negativity) and 3 false negative (microscopic test negativity with culture test positivity) samples. The prevalence of tinea infection was 47.01% in the population of 51 children. The microscopic test of a sample was efficient by 87.5%, in arriving at a positive result on diagnosis, when its culture test was positive; and, this test was efficient by 76.4%, in arriving at a negative result, when its culture test was negative. But, the post-test probability value of a sample with both microscopic and culture tests would be correct in distinguishing a sample from a sick or a healthy child with a chance of 71.5%. However, since the sensitivity of the analysis is 87.5%, the microscopic test positivity would be easier to detect in the presence of infection. In conclusion, it could be stated that Trychophyton rubrum was the most prevalent species; sensitivity and specificity of treating the infection, by antifungal therapy before ascertaining by the culture method remain as 0.8751 and 0.7642, respectively. A correct/coveted diagnostic method of fungal infection would be could be achieved by modern molecular methods (matrix-assisted laser desorption ionisation-time of flight mass spectrometry or fluorescence in situ hybridization or enzyme-linked immunosorbent assay [ELISA] or restriction fragment length polymorphism or DNA/RNA probes of known fungal taxa) in advanced laboratories.

Intrasaccular Flow Disruption in Acutely Ruptured Aneurysms: A Multicenter Retrospective Review of the Use of the WEB

BACKGROUND AND PURPOSE

Use of the WEB intra-aneurysmal flow-disruption device in unruptured wide-neck bifurcation aneurysms has proven safety and efficacy. However, ruptured aneurysms are underrepresented in existing studies. This retrospective multicenter study describes the use of the WEB in patients with a ruptured intracranial aneurysm.

MATERIALS AND METHODS

Ten centers contributed to this study. Clinical and procedural data of 47 patients with 52 aneurysms were analyzed retrospectively together with follow-up angiographies.

RESULTS

There were 37 anterior and 15 posterior circulation aneurysms with a neck size of ≥4 mm in 49 of 52 (94%) aneurysms; 45 (87%) aneurysms were <10 mm, and 2 were partially thrombosed. Successful placement of the WEB was possible in every case. Adjunctive devices were used in 8 of 52 (15%) aneurysms. Thromboembolic events were observed in 4 of 52 (8%) patients. Adverse events occurred in 15 patients with 16 aneurysms, 9 of which were potentially related to the WEB procedure (3 thromboembolic events, 5 protrusions, and 1 perforations; 2 perforations were caused by the wire or catheter), but none had a clinical impact. Four patients were retreated. Short-term follow-up in 25 of 39 patients revealed complete occlusion in 15 of 25 (60%), 5 of 25 (20%) with residual neck, and 5 of 25 (20%) with residual aneurysm filling. Short- to midterm imaging in 9 of 25 patients revealed complete occlusion in 5 (55.6%), residual neck in 2 (22%), and residual aneurysm filling in 2 (22%). Of 47 patients, 23 (49%) had an mRS score of 0, 1, or 2; 13 (28%) had an mRS score of 3 or 4; and none had an mRS score of 5 at discharge.

CONCLUSIONS

This retrospective series showed good procedural safety, feasibility, and stability of midterm occlusion in ruptured wide-neck bifurcation aneurysms.

Raman modes, dipole moment and chirality in periodically positioned Au8clusters

The solution-based assembly of h-Au₈clusters into a local periodic structure (LPS) of periodicity 1.47 nm with negative chirality as confirmed by experimental and theoretical analyses exhibits excitonic couplet state.

RMS Pictorial Scale (RMS-PS): an innovative scale for the assessment of child's dental anxiety

BACKGROUND

Dental anxiety assessment for young children is as important as performing their treatment. Appropriate knowledge of patient's anxiety boosts confidence and will help us to review potential management options specific to every child.

AIM

This study aimed to validate (RMS) Pictorial Scale (RMS-PS) and to compare it with Venham Picture Test (VPT) and Facial image scale (FIS) in measuring dental anxiety for young children during their first dental visit.

MATERIALS AND METHODS

A total of 102 healthy children aged between 4 and 14 years during their first dental visit were randomly selected for the study. Childs anxiety level was measured using three different scales namely (i) RMS-PS (ii) VPT, and (iii) FIS.

STATISTICAL ANALYSIS

Student t test was used to compare the scores obtained from all the three scales. Pearson correlation test was used to obtain correlation among the scales used in the study.

RESULTS

A strong correlation (0·76) was found between the VPT and RMS-PS, and a moderate correlation (0.5) was found between RMS-PS and FIS, indicating good validity for the RMS-PS.

CONCLUSIONS

The findings of this study suggest that the RMS-PS can be a newer and easiest means for the assessment of dental anxiety for young children in a clinical context.