Acene Ring Size Optimization in Fused Lactam Polymers Enabling High n-Type Organic Thermoelectric Performance.

Three n-type fused lactam semiconducting polymers were synthesized for thermoelectric and transistor applications via a cheap, highly atom-efficient, and nontoxic transition-metal free aldol polycondensation. Energy level analysis of the three polymers demonstrated that reducing the central acene core size from two anthracenes (A-A), to mixed naphthalene-anthracene (A-N), and two naphthalene cores (N-N) resulted in progressively larger electron affinities, thereby suggesting an increasingly more favorable and efficient solution doping process when employing 4-(2,3-dihydro-1,3-dimethyl-1H-benzimidazol-2-yl)-N,N-dimethylbenzenamine (N-DMBI) as the dopant. Meanwhile, organic field effect transistor (OFET) mobility data showed the N-N and A-N polymers to feature the highest charge carrier mobilities, further highlighting the benefits of aryl core contraction to the electronic performance of the materials. Ultimately, the combination of these two factors resulted in N-N, A-N, and A-A to display power factors (PFs) of 3.2 µW m-1 K-2, 1.6 µW m-1 K-2, and 0.3 µW m-1 K-2, respectively, when doped with N-DMBI, whereby the PFs recorded for N-N and A-N are among the highest reported in the literature for n-type polymers. Importantly, the results reported in this study highlight that modulating the size of the central acene ring is a highly effective molecular design strategy to optimize the thermoelectric performance of conjugated polymers, thus also providing new insights into the molecular design guidelines for the next generation of high-performance n-type materials for thermoelectric applications.

Atypical Presentation of Acute Freiberg Disease.

Freiberg disease is a chronic progressive condition that results in pain and loss of normal function of the metatarsophalangeal joint (MTPJ). We describe a case of acute Freiberg disease secondary to a short course of oral steroids. The patient presented with an acute metatarsal head fracture that was managed successfully with open reduction and internal fixation. Although a rare complication of corticosteroid use, physicians having patients start taking steroids must remember the risk of osteonecrosis.

Solution-processable polymers of intrinsic microporosity for gas-phase carbon dioxide photoreduction.

Four solution-processable, linear conjugated polymers of intrinsic porosity are synthesised and tested for gas phase carbon dioxide photoreduction. The polymers' photoreduction efficiency is investigated as a function of their porosity, optical properties, energy levels and photoluminescence. All polymers successfully form carbon monoxide as the main product, without the addition of metal co-catalysts. The best performing single component polymer yields a rate of 66 µmol h-1 m-2, which we attribute to the polymer exhibiting macroporosity and the longest exciton lifetimes. The addition of copper iodide, as a source of a copper co-catalyst in the polymers shows an increase in rate, with the best performing polymer achieving a rate of 175 µmol h-1 m-2. The polymers are active for over 100 h under operating conditions. This work shows the potential of processable polymers of intrinsic porosity for use in the gas phase photoreduction of carbon dioxide towards solar fuels.

Analysis of neuron-specific enolase and S100B as biomarkers of cognitive decline following surgery in older people.

BACKGROUND/AIMS: Post-operative cognitive decline is frequent in older individuals following major surgery; however, biomarkers of this decline are less clearly defined. METHODS: Sixty-eight participants over the age of 60 provided blood samples at baseline and 24 h post-surgery. Cognitive decline was measured at baseline and 52 weeks post-surgery using the Cambridge Assessment for Mental Disorder in the Elderly, section B (CAMCOG) score. Plasma levels of neuron-specific enolase (NSE) and S100B were measured by ELISA. RESULTS: Baseline NSE and the change in NSE levels between baseline and 24 h were correlated with the change in CAMCOG score between baseline and 52 weeks. CONCLUSION: NSE concentrations may be a useful predictor of individuals at risk of more severe long-term cognitive decline.

Sagittal endplate morphology of the lower lumbar spine.

SUMMARY OF BACKGROUND DATA: The sagittal profile of lumbar endplates is discrepant from current simplified disc replacement and fusion device design. Endplate concavity is symmetrical in the coronal plane but shows considerable variability in the sagittal plane, which may lead to implant-endplate mismatch. OBJECTIVE: The aim of this investigation is to provide further analysis of the sagittal endplate morphology of the mid to lower lumbar spine study (L3­S1), thereby identifying the presence of common endplate shape patterns across these levels and providing morphological reference values complementing the findings of previous studies. STUDY DESIGN: Observational study. METHODS: A total of 174 magnetic resonance imaging (MRI) scans of the adult lumbar spine from the digital archive of our centre, which met the inclusion criteria, were studied. Superior (SEP) and inferior (IEP) endplate shape was divided into flat (no concavity), oblong (homogeneous concavity) and ex-centric (inhomogeneous concavity). The concavity depth (ECD) and location of concavity apex (ECA) relative to endplate diameter of the vertebrae L3­S1 were determined. RESULTS: Flat endplates were only predominant at the sacrum SEP (84.5%). The L5 SEP was flat in 24.7% and all other endplates in less than 10%. The majority of endplates were concave with a clear trend of endplate shape becoming more ex-centric from L3 IEP (56.9% oblong vs. 37.4% ex-centric) to L5 IEP (4% oblong vs. 94.3% ex-centric). Ex-centric ECA were always found in the posterior half of the lumbar endplates. Both the oblong and ex-centric ECD was 2-3 mm on average with the IEP of a motion segment regularly possessing the greater depth. A sex- or age-related difference could not be found. CONCLUSION: The majority of lumbar endplates are concave, while the majority of sacral endplates are flat. An oblong and an ex-centric endplate shape can be distinguished, whereby the latter is more common at the lower lumbar levels. The apex of the concavity of ex-centric discs is located in the posterior half of the endplate and the concavity of the inferior endplate is deeper than that of the superior endplate. Based on the above, the current TDR and ALIF implant design does not sufficiently match the morphology of lumbar endplates in the sagittal plane.

Never events in orthopaedics: A nationwide data analysis and guidance on preventative measures.

BACKGROUND: Never Events (NE) are serious clinical incidents that are wholly preventable if appropriate institutional safeguards are in place and followed. They are often used as a surrogate of the quality of healthcare delivered by an institution. Most NEs are surgical and orthopaedic surgery is one of the most involved specialties. OBJECTIVE: The aim of this study was to identify common NE themes associated with orthopaedics within the National Health Service (NHS) of England. METHOD: We conducted an observational study analysing the annual NE data published by the NHS England from 2012 to 2020 to collate all orthopaedic surgery-related NE and construct relevant recurring themes. RESULTS: We identified 460 orthopaedic NE out of a total of 3247 (14.16%) reported NE to NHS England. There were 206 Wrong implants/prostheses under 8 different themes. Wrong hip and knee prosthesis were the commonest "wrong implants" (n = 94; 45.63% and n = 91; 44.17% respectively). There were 197 "wrong-site surgery" incidents in 22 different themes. The commonest of these was the laterality problems accounting for 64 (32.48%) incidents followed by 63 (31.97%) incidents of wrong spinal level interventions. There were 18 (9.13%) incidents of intervention on the wrong patients and 17 (8.62%) wrong incisions. Retained pieces of instruments were the commonest retained foreign body with 15 (26.13%) incidents. The next categories were retained drill parts and retained instruments with 13 (22.80%) incidents each. CONCLUSION: We identified 47 different themes of NE specific to orthopaedic surgery. Awareness of these themes would help in their prevention. Site marking can be challenging in the presence of cast and on operating on the digits and spine. Addition of a real-time intra-operative implant scan to the National Joint Registry can avoid wrong implant selection while fiducial markers, intraoperative imaging, O-arm navigation, and second time-out could help prevent wrong level spinal surgery.

Oligoethylene Glycol Side Chains Increase Charge Generation in Organic Semiconductor Nanoparticles for Enhanced Photocatalytic Hydrogen Evolution.

Organic semiconductor nanoparticles (NPs) composed of an electron donor/acceptor (D/A) semiconductor blend have recently emerged as an efficient class of hydrogen-evolution photocatalysts. It is demonstrated that using conjugated polymers functionalized with (oligo)ethylene glycol side chains in NP photocatalysts can greatly enhance their H2 -evolution efficiency compared to their nonglycolated analogues. The strategy is broadly applicable to a range of structurally diverse conjugated polymers. Transient spectroscopic studies show that glycolation facilitates charge generation even in the absence of a D/A heterojunction, and further suppresses both geminate and nongeminate charge recombination in D/A NPs. This results in a high yield of photogenerated charges with lifetimes long enough to efficiently drive ascorbic acid oxidation, which is correlated with greatly enhanced H2 -evolution rates in the glycolated NPs. Glycolation increases the relative permittivity of the semiconductors and facilitates water uptake. Together, these effects may increase the high-frequency relative permittivity inside the NPs sufficiently, to cause the observed suppression of exciton and charge recombination responsible for the high photocatalytic activities of the glycolated NPs.

Zone-refinement effect in small molecule-polymer blend semiconductors for organic thin-film transistors.

The blend films of small-molecule semiconductors with insulating polymers exhibit not only excellent solution processability but also superior performance characteristics in organic thin-film transistors (OTFTs) over those of neat small-molecule semiconductors. To understand the underlying mechanism, we studied triethylsilylethynyl anthradithiophene (TESADT) with small amounts of impurity formed by weak UV exposure. OTFTs with neat impure TESADT had drastically reduced field-effect mobility (<10(-5) cm(2)/(V s)), and a disappearance of the high-temperature crystal phase was observed for neat impure TESADT. However, the mobility of the blend films of the UV-exposed TESADT with poly(α-methylstyrene) (PαMS) is recovered to that of a fresh TESADT-PαMS blend (0.040 cm(2)/(V s)), and the phase transition characteristics partly return to those of fresh TESADT films. These results are corroborated by OTFT results on "aged" TIPS-pentacene. These observations, coupled with the results of neutron reflectivity study, indicate that the formation of a vertically phase-separated layer of crystalline small-molecule semiconductors allows the impurity species to remain preferentially in the adjacent polymer-rich layer. Such a "zone-refinement effect" in blend semiconductors effectively removes the impurity species that are detrimental to organic electronic devices from the critical charge-transporting interface region.

Extra-articular fixation for treatment of Lisfranc injury.

Lisfranc injuries are not very common. Surgical options available for treatment of Lisfranc injuries have produced chronic pain and disability due to the damage to the articular surface, leading to early arthritis. We describe the technique of extra-articular fixation using dorsal plates for Lisfranc injury, avoiding any damage to the articular surface.

Fused electron deficient semiconducting polymers for air stable electron transport.

Conventional semiconducting polymer synthesis typically involves transition metal-mediated coupling reactions that link aromatic units with single bonds along the backbone. Rotation around these bonds contributes to conformational and energetic disorder and therefore potentially limits charge delocalisation, whereas the use of transition metals presents difficulties for sustainability and application in biological environments. Here we show that a simple aldol condensation reaction can prepare polymers where double bonds lock-in a rigid backbone conformation, thus eliminating free rotation along the conjugated backbone. This polymerisation route requires neither organometallic monomers nor transition metal catalysts and offers a reliable design strategy to facilitate delocalisation of frontier molecular orbitals, elimination of energetic disorder arising from rotational torsion and allowing closer interchain electronic coupling. These characteristics are desirable for high charge carrier mobilities. Our polymers with a high electron affinity display long wavelength NIR absorption with air stable electron transport in solution processed organic thin film transistors.

Organic solar cells using a high-molecular-weight benzodithiophene-benzothiadiazole copolymer with an efficiency of 9.4%.

A high molecular weight donor-acceptor conjugated polymer is synthesized using the Suzuki polycondensation method. Using this polymer, a single-junction bulk-heterojunction solar cell is fabricated giving a power conversion efficiency of 9.4% using a fullerene-modified ZnO interlayer at the cathode contact.

Prevalence of insomnia in patients with chronic back pain.

PURPOSE: To estimate the prevalence of insomnia in patients with chronic back pain, and to correlate insomnia with severity of back pain and disability. METHODS: 63 women and 57 men aged 24 to 83 (mean, 55) years who presented with chronic back pain for >6 months were asked to complete a self-administered questionnaire to evaluate the Insomnia Severity Index (ISI), Oswestry Disability Index (ODI), and Numerical Rating Scale (NRS) for back pain. RESULTS: Of the 120 patients, 25 had no insomnia, 39 had sub-threshold insomnia, and 56 had clinically significant insomnia. According to the ODI, disability was minimal in 12 patients, moderate in 38, severe in 43, bed-binding in 26, and crippling in one. Of the 120 patients, 91 rated their NRS for back pain as 5 to 10 and 29 rated it as 1 to 4. Correlation was stronger between ISI and ODI than between ISI and NRS for back pain (r=0.59 vs. r=0.38). CONCLUSION: 47% of patients with chronic back pain had insomnia. The ODI was more reliable than the NRS for back pain to detect insomnia. Back pain should be treated early to avoid serious health problems associated with insomnia.

Posttraumatic chronic patellar dislocation treated by distal femoral osteotomy and medial patellofemoral ligament reconstruction.

Chronic patellar dislocation is a rare condition where the patella remains dislocated throughout knee range of motion during flexion and extension. In adults, the delayed presentation of this condition is often due to symptoms caused by the onset of severe secondary osteoarthritis. To the authors' knowledge, all of the cases reported in the literature have been treated by patellofemoral or total knee replacements depending on patient age and the extent of the arthritis. This article describes a rare case of a 22-year-old woman who sustained a traumatic chronic patellar dislocation for 5 months. Clinical examination revealed a valgus deformity of the left leg secondary to childhood injury and that the patella lay lateral to the lateral femoral condyle throughout flexion and extension. Radiographs of the knee revealed patellar dislocation. Long-leg radiographs of the left leg showed an anatomic tibiofemoral angle of 17° valgus. The anatomical (74°) and mechanical (80°) lateral distal femoral angles were abnormal, whereas the medial proximal tibial angle (87°) was normal, confirming that the valgus deformity was due to the abnormal distal femur. The authors performed a distal femoral osteotomy to correct the valgus deformity. Medial patellofemoral ligament reconstruction using a hamstring autograft was performed to stabilize the patella.

Synthesis of electron-poor hexa-peri-hexabenzocoronenes.

The oxidative cyclodehydrogenation of electron-poor arenes was achieved using DDQ-CF(3)SO(3)H resulting in hexa-peri-hexabenzocoronenes with electron withdrawing Br, F and CF(3) groups. This method will lead to their expansion into a new class of electron transport materials.

Synthesis and charge transport studies of stable, soluble hexacenes.

Acenes larger than pentacene are predicted to possess enticing electronic properties, but are insoluble and prone to rapid decomposition. Utilizing a combination of functionalization strategies, we present stable, solution-processable hexacenes and an evaluation of their hole and electron transport properties.

Optimised anaesthesia to reduce post operative cognitive decline (POCD) in older patients undergoing elective surgery, a randomised controlled trial.

BACKGROUND: The study determined the one year incidence of post operative cognitive decline (POCD) and evaluated the effectiveness of an intra-operative anaesthetic intervention in reducing post-operative cognitive impairment in older adults (over 60 years of age) undergoing elective orthopaedic or abdominal surgery. METHODS AND TRIAL DESIGN: The design was a prospective cohort study with a nested randomised, controlled intervention trial, using intra-operative BiSpectral index and cerebral oxygen saturation monitoring to enable optimisation of anaesthesia depth and cerebral oxygen saturation in older adults undergoing surgery. RESULTS: In the 52 week prospective cohort study (192 surgical patients and 138 controls), mild (χ(2) = 17.9 p<0.0001), moderate (χ(2) = 7.8 p = 0.005) and severe (χ(2) = 5.1 p = 0.02) POCD were all significantly higher after 52 weeks in the surgical patients than among the age matched controls. In the nested RCT, 81 patients were randomized, 73 contributing to the data analysis (34 intervention, 39 control). In the intervention group mild POCD was significantly reduced at 1, 12 and 52 weeks (Fisher's Exact Test p = 0.018, χ(2) = 5.1 p = 0.02 and χ(2) = 5.9 p = 0.015), and moderate POCD was reduced at 1 and 52 weeks (χ(2) = 4.4 p = 0·037 and χ(2) = 5.4 p = 0.02). In addition there was significant improvement in reaction time at all time-points (Vigilance Reaction Time MWU Z = -2.1 p = 0.03, MWU Z = -2.7 p = 0.004, MWU Z = -3.0 p = 0.005), in MMSE at one and 52 weeks (MWU Z = -2.9 p = 0.003, MWU Z = -3.3 p = 0.001), and in executive function at 12 and 52 weeks (Trail Making MWU Z = -2.4 p = .0.018, MWU Z = -2.4 p = 0.019). CONCLUSION: POCD is common and persistent in older adults following surgery. The results of the nested RCT indicate the potential benefits of intra-operative monitoring of anaesthetic depth and cerebral oxygenation as a pragmatic intervention to reduce post-operative cognitive impairment. TRIAL REGISTRATION: Controlled-Trials.com ISRCTN39503939.

Impact of reinfusion drains on hemoglobin level in total knee arthroplasty.

We conducted this study to determine the effect of reinfusion drains on the difference in hemoglobin (Hb) levels before and after total knee arthroplasty. Of the 158 patients who underwent total knee arthroplasty on one side, 74 had autologous blood transfusion through reinfusion drains (group 1); the other 84 did not have autologous blood transfusion, but ordinary suction drains were used to drain the wound during the immediate postoperative period (group 2). Mean preoperative Hb levels were 13.6 g/dL for group 1 (SD, 1.4 g/dL; range, 10.4-18.1 g/dL) and 13.6 g/dL for group 2 (SD, 1.3 g/dL; range, 10.0-16.7 g/dL). Mean postoperative Hb levels were 10.7 g/dL for group 1 (SD, 1.5 g/dL; range, 7.9-16.5 g/dL) and 10.7 g/dL for group 2 (SD, 1.6 g/dL; range, 5.4-13.6 g/dL). The difference in Hb levels between the groups before and after the surgery was analyzed with t test and found to be not significant (P = .76). The reinfusion drain cost pound 36.43 ( approximately US$58.87) more than the suction drain. Autologous blood from reinfusion drains did not significantly improve postoperative Hb levels. Further use of reinfusion drain is not cost-beneficial.

Spondylodiscitis due to Prevotella associated with ovarian mass--a rare case report and review of literature.

BACKGROUND: Spondylodiscitis is commonly caused by aerobic bacteria. Of all the spinal infections, anaerobic organisms account for less than 3% and are usually seen in postoperative patients. CASE DESCRIPTION: We report a rare case of spontaneous onset of spondylodiscitis caused by anaerobe Prevotella that led to the diagnosis of serous cystadenofibroma of the ovaries. CONCLUSION: The finding of Prevotella species in musculoskeletal infection should prompt investigation of the genitourinary system.