Health-related quality of life across disease stages in patients with amyotrophic lateral sclerosis: results from a real-world survey

BACKGROUND

Amyotrophic lateral sclerosis (ALS) is characterized by a rapid disease course, with disease severity being associated with declining health-related quality of life (HRQoL) in persons living with ALS (pALS). The main objective of this study was to assess the impact of disease progression on HRQoL across King's, Milano-Torino Staging (MiToS), and physician-judgement clinical staging. Additionally, we evaluated the impact of the disease on the HRQoL of care partners (cALS).

METHODS

Data were sourced from the Adelphi ALS Disease Specific Programme (DSP)™, a cross-sectional survey of neurologists, pALS and cALS presenting in a real-world clinical setting between July 2020 and March 2021 in Europe and the United States.

RESULTS

Neurologists (n = 142) provided data for 880 pALS. There were significant negative correlations between all three clinical staging systems and EuroQol (European Quality of Life) Five Dimension Five Level Scale (EQ-5D-5L) utility scores and visual analogue scale (VAS) ratings. Although not all differences were significant, 5-item Amyotrophic Lateral Sclerosis Assessment Questionnaire (ALSAQ-5) scores showed a stepwise increase in HRQoL impairment at each stage of the disease regardless of the staging system. At later stages, high levels of fatigue and substantial activity impairment were reported. As pALS disease states progressed, cALS also experienced a decline in HRQoL and increased burden.

CONCLUSIONS

Across outcomes, pALS and cALS generally reported worse outcomes at later stages of the disease, highlighting an unmet need in this population for strategies to maximise QoL despite disease progression. Recognition and treatment of symptoms such as pain and fatigue may lead to improved outcomes for pALS and cALS.

Factors associated with increased radiation exposure in the fixation of proximal femoral fractures

INTRODUCTION

When using radiation intraoperatively, a surgeon should aim to keep the radiation dose as low as is reasonably achievable to obtain the therapeutic goal. We aimed to investigate factors associated with increased radiation exposure in fixation of proximal femur fractures.

METHODS

We assessed 369 neck of femur fractures over a 1-year period in a district general hospital. All hip fracture subtypes that had undergone surgical fixation were included. We assessed the relationship between type of fracture, implants used and surgeon level of experience with the dose-area product (DAP; cGy/cm2) and screening time (dS). We also looked at the quality of reduction and fixation and its effect on the radiation exposure.

RESULTS

A total of 184 patients were included in our analysis; 185 patients who were treated with hip arthroplasty were excluded. There was a significant association between higher DAP and fracture subtype (p = 0.001), fracture complexity (p < 0.001), if an additional implant was used (p = 0.001), if fixation was satisfactory (p = 0.002) and operative time (p < 0.001). DAP was higher with a proximal femoral nail than with a dynamic hip screw, especially when a long nail was used. There was some evidence of an association between the surgeon's level of experience and DAP exposure, although this was not statistically significant (p = 0.069).

CONCLUSIONS

Increased radiation in proximal femur fractures is seen in the fixation of complex fractures, some subtypes, with certain types of implants used and if an additional implant was required. Surgeon seniority did not result in less radiation exposure, which is in contrast to other published studies.

In silico interrogation of the miRNAome of infected hematopoietic cells to predict processes important for human cytomegalovirus latent infection

Human cytomegalovirus (HCMV) latency in CD34+ progenitor cells is the outcome of a complex and continued interaction of virus and host that is initiated during very early stages of infection and reflects pro- and anti-viral activity. We hypothesized that a key event during early infection could involve changes to host miRNAs, allowing for rapid modulation of the host proteome. Here, we identify 72 significantly upregulated miRNAs and three that were downregulated by 6hpi of infection of CD34+ cells which were then subject to multiple in silico analyses to identify potential genes and pathways important for viral infection. The analyses focused on the upregulated miRNAs and were used to predict potential gene hubs or common mRNA targets of multiple miRNAs. Constitutive deletion of one target, the transcriptional regulator JDP2, resulted in a defect in latent infection of myeloid cells; interestingly, transient knockdown in differentiated dendritic cells resulted in increased viral lytic IE gene expression, arguing for subtle differences in the role of JDP2 during latency establishment and reactivation of HCMV. Finally, in silico predictions identified clusters of genes with related functions (such as calcium signaling, ubiquitination, and chromatin modification), suggesting potential importance in latency and reactivation. Consistent with this hypothesis, we demonstrate that viral IE gene expression is sensitive to calcium channel inhibition in reactivating dendritic cells. In conclusion, we demonstrate HCMV alters the miRNAome rapidly upon infection and that in silico interrogation of these changes reveals new insight into mechanisms controlling viral gene expression during HCMV latency and, intriguingly, reactivation.

Three strategies when physicians provide complex information in interactions with patients: How to recognize and measure them

OBJECTIVE

To define and operationalize three taught strategies for providing information in interactions with patients using videos collected in a randomized controlled trial (RCT).

METHODS

This was a qualitative exploratory study embedded in a randomized controlled design, using microanalysis of face-to-face dialogue as an inductive video analysis method to operationalize physicians' use of three information-provision strategies. Data were 34 video-recorded simulated (but unscripted) interactions between 17 physicians and 34 multiple sclerosis patients collected before and after a brief course on information provision. We operationalized (1) mapping the patient's preferences and (2) checking the patient's understanding, and pauses indicative of (3) portioning information.

RESULTS

Results are detailed analytical definitions, criteria, and assessable, quantifiable outcomes for each of the three strategies. Patients responded to portioning pauses as expected: whereas 91% of these pauses elicited an immediate patient response, only 23% of non-portioning pauses did so.

CONCLUSION

Our methods revealed how to define and evaluate information sharing strategies physicians used within the contingencies of clinical interaction.

PRACTICE IMPLICATIONS

Findings provide applicable methods to teach, analyze, and evaluate information sharing strategies and indications for further training.

Bragg coherent diffraction imaging of single 20 nm Pt particles at the ID01-EBS beamline of ESRF

This work demonstrates three-dimensional Bragg coherent diffraction imaging of single 20 nm Pt particles at the ID01-EBS beamline of ESRF.

Electronic or catalytic properties can be modified at the nanoscale level. Engineering efficient and specific nanomaterials requires the ability to study their complex structure–property relationships. Here, Bragg coherent diffraction imaging was used to measure the three-dimensional shape and strain of platinum nanoparticles with a diameter smaller than 30 nm, i.e. significantly smaller than any previous study. This was made possible by the realization of the Extremely Brilliant Source of ESRF, The European Synchrotron. This work demonstrates the feasibility of imaging the complex structure of very small particles in three dimensions and paves the way towards the observation of realistic catalytic particles.

High lead level in the Alps in XIXth century, learning from the analysis of 138 historical hair stands

Analysis of hair is known to provide useful information about environmental and toxic exposures. Very little historical use has been made of this type of investigation. Here we study 138 human hair samples from 19th century in France. In order to examine the potential association between contamination and historical health impacts, we characterized contamination by 33 elements in a set of hair strands sampled during the last quarter of the 19th century in the Savoy region of France. After a selected washing step on 138 hair strands conserved at the Museum National d'Histoire Naturelle in Paris (France), we assessed the presence of inorganics by ICP/MS, and lead level was higher than values reported in literature. We then compared concentrations and distributions between women and men, sampling locations and crossing gender and geographical origin. Hair lead level was high throughout Savoy at the end of the 19th century: significantly higher for people living in towns or industrial valleys, and lower for those of countryside and mountains areas. Environmental and economic changes (industrialization and urbanization with water adduction and leaded paints), living habits (kitchenware, cosmetics, wine, and tobacco), and local features (mines exploitation, railroad development, and industrialized narrow valleys) could be envisaged for explaining the level of lead contamination. In the same period, the two main industrial valleys of Savoy (Maurienne and Tarentaise) had high rates of endemic goiter and cretinism and among the highest hair lead levels. Other lines of evidence will need to be explore to investigate a possible link between historical Pb exposure and goiter in the study area.

Effect of type 1 tympanoplasty on the quality of life of patients suffering from chronic otitis media (safe type)

Background

Chronic otitis media (COM) remains a major public health issue and is associated with relentless discharge from the ear, pain, significant functional limitation of hearing, leading to communication problems and frequent specialist visits.

Aims

To assess the improvement in quality of life of patients of COM (safe type) and surgical success in terms of graft uptake and improvement in hearing.

Patients and Methods

A prospective questionnaire-based outcome study was directed in 100 patients with COM who were treated with Type I Tympanoplasty at our institution between May 2018 and May 2020. All patients were asked to fill Modified Chronic Otitis Media 4 (COM-4) survey before operation and 3 months after operation. Preoperative and postoperative total ear scores, audiological results, postoperative graft uptake were assessed.

Results

The correlation between preoperative and postoperative assessment by questionnaire was statistically critical (P < 0.001). There was significant improvement in hearing postoperatively (P < 0.001). Effective graft uptake was seen in 80%.

Conclusion

The current study emphasizes that Type 1 Tympanoplasty fundamentally improves quality of life of patients in terms of physical suffering, hearing loss, emotional distress postoperatively.

1414 The Impact Of COVID-19 On Individuals with Neck of Femur Fracture in The United Kingdom: A Systematic Review and Meta-analysis

Aim

All Neck of Femur fracture patients have a significant 30 – day mortality despite efforts to improve their outcomes. Incidence of NOF cases remained high during the pandemic in the UK and as a result numerus cases were complicated with SARS-CoV-2 infection. We performed a systematic review and meta-analysis of all UK published studies related to NOF fractures and 30-day mortality outcomes during the COVID 19 pandemic.

Method

A systematic review and meta-analysis was performed and reported as per the PRISMA checklist. Two reviewers independently searched on Medline for UK studies that were published between 1stof March 2020 and 1stof November 2020. Outcomes compared were 30-day mortality, time to surgery and anaesthetic risk.

Results

A total of 5 articles were included in our study. These studies were all case series with evidence level 3 or 4. A total of 286 patients complicated with COVID infection with a range of 30-day mortality 30.5%-50%. OR 6.02(95CI: 4.10-8.85), Chi24.82, I2 58%. Increased time to surgery due to Coronavirus related delays was also noted for the majority of studies. Mortality scores (Charlson Comorbidity Index, Nottingham Hip fracture score) failed to accurately predict the mortality risk.

Conclusions

Concurrent infection of COVID -19 in patients with NOF fractures increases the 30-day mortality 6 times compared to the negative group. Efforts should be made to optimise time to surgery as well as postoperative care via higher dependency units. Updates in mortality predicting scores is deemed necessary to include the SARS-CoV-2 infection as a factor.

Energy-dispersive X-ray micro Laue diffraction on a bent gold nanowire

This article reports on energy-dispersive micro Laue (µLaue) diffraction of an individual gold nanowire that was mechanically deformed in three-point bending geometry using an atomic force microscope. The nanowire deformation was investigated by scanning the focused polychromatic X-ray beam along the nanowire and recording µLaue diffraction patterns using an energy-sensitive pnCCD detector that permits measurement of the angular positions of the Laue spots and the energies of the diffracted X-rays simultaneously. The plastic deformation of the nanowire was shown by a bending of up to 3.0 ± 0.1°, a torsion of up to 0.3 ± 0.1° and a maximum deformation depth of 80 ± 5 nm close to the position where the mechanical load was applied. In addition, extended Laue spots in the vicinity of one of the clamping points indicated the storage of geometrically necessary dislocations with a density of 7.5 × 1013 m-2. While µLaue diffraction with a non-energy-sensitive detector only gives access to the deviatoric strain, the energy sensitivity of the employed pnCCD offers absolute strain measurements with a resolution of 1%. Here, the residual strain after complete unloading of the nanowire amounted to maximum tensile and compressive strains of the order of +1.2 and -3%, which is comparable to the actual resolution limit. The combination of white-beam µLaue diffraction using an energy-sensitive pixel detector with nano-mechanical testing opens up new possibilities for the study of mechanical behavior at the nanoscale.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Multi-wavelength Bragg coherent X-ray diffraction imaging of Au particles

Multi-wavelength (mw) Bragg coherent X-ray diffraction imaging (BCDI) is demonstrated on a single Au particle. The multi-wavelength Bragg diffraction patterns are inverted using conventional phase-retrieval algorithms where the dilation of the effective pixel size of a pixelated 2D detector caused by the variation of the X-ray beam energy is mitigated by interpolating the raw data. The reconstructed Bragg electron density and phase field are in excellent agreement with the results obtained from conventional rocking scans of the same particle. Voxel sizes of about 63 nm3 are obtained for reconstructions from both approaches. Phase shifts as small as 0.41 rad, which correspond to displacements of 14 pm and translate into strain resolution better than 10−4 in the Au particle, are resolved. The displacement field changes shape during the experiment, which is well reproduced by finite element method simulations considering an inhomogeneous strained carbon layer deposited on the Au particle over the course of the measurements. These experiments thus demonstrate the very high sensitivity of BCDI and mw-BCDI to strain induced by contaminations. Furthermore, mw-BCDI offers new opportunities for in situ and operando 3D strain imaging in complex sample environments.

Observational study of the medical management of patients with peripheral artery disease

BACKGROUND

Previous research has suggested that patients with peripheral artery disease (PAD) are not offered adequate risk factor modification, despite their high cardiovascular risk. The aim of this study was to assess the cardiovascular profiles of patients with PAD and quantify the survival benefits of target-based risk factor modification.

METHODS

The Vascular and Endovascular Research Network (VERN) prospectively collected cardiovascular profiles of patients with PAD from ten UK vascular centres (April to June 2018) to assess practice against UK and European goal-directed best medical therapy guidelines. Risk and benefits of risk factor control were estimated using the SMART-REACH model, a validated cardiovascular prediction tool for patients with PAD.

RESULTS

Some 440 patients (mean(s.d.) age 70(11) years, 24·8 per cent women) were included in the study. Mean(s.d.) cholesterol (4·3(1·2) mmol/l) and LDL-cholesterol (2·7(1·1) mmol/l) levels were above recommended targets; 319 patients (72·5 per cent) were hypertensive and 343 (78·0 per cent) were active smokers. Only 11·1 per cent of patients were prescribed high-dose statin therapy and 39·1 per cent an antithrombotic agent. The median calculated risk of a major cardiovascular event over 10 years was 53 (i.q.r. 44-62) per cent. Controlling all modifiable cardiovascular risk factors based on UK and European guidance targets (LDL-cholesterol less than 2 mmol/l, systolic BP under 140 mmHg, smoking cessation, antiplatelet therapy) would lead to an absolute risk reduction of the median 10-year cardiovascular risk by 29 (20-38) per cent with 6·3 (4·0-9·3) cardiovascular disease-free years gained.

CONCLUSION

The medical management of patients with PAD in this secondary care cohort was suboptimal. Controlling modifiable risk factors to guideline-based targets would confer significant patient benefit.

Experimental realization of a Rydberg optical Feshbach resonance in a quantum many-body system

Feshbach resonances are a powerful tool to tune the interaction in an ultracold atomic gas. The commonly used magnetic Feshbach resonances are specific for each species and are restricted with respect to their temporal and spatial modulation. Optical Feshbach resonances are an alternative which can overcome this limitation. Here, we show that ultra-long-range Rydberg molecules can be used to implement an optical Feshbach resonance. Tuning the on-site interaction of a degenerate Bose gas in a 3D optical lattice, we demonstrate a similar performance compared to recent realizations of optical Feshbach resonances using intercombination transitions. Our results open up a class of optical Feshbach resonances with a plenitude of available lines for many atomic species and the possibility to further increase the performance by carefully selecting the underlying Rydberg state.

In situ Bragg coherent X-ray diffraction during tensile testing of an individual Au nanowire

Systematic tensile tests were performed on single defect-free 〈110〉 Au nanowires grown by physical vapor deposition while simultaneously recording three-dimensional Bragg peaks using coherent X-rays. The trajectory of three-dimensional Bragg peaks in reciprocal space during tensile testing allowed for measurements of the evolution of strains and rotations of the nanowire, thus sensitively uncovering the full deformation geometry of the nanowire. The transition from elastic to plastic deformation is accompanied by rotations of the nanowire as quantified by analysis of the motion of Bragg peaks, showing the importance of boundary conditions in interpreting nanoscale mechanical deformations.

[Innovation in transport of critical care patients]

The differentiation of specialist care means that not every hospital can meet specific care requirements. Because of this, frequent transport of critical care patients is necessary. In most circumstances, regular ambulance transport is used, either with or without an accompanying physician. In some cases, a mobile intensive care unit (MICU) can be deployed. However, the MICU is not 24/7 operational in our area and significant waiting times can occur. Additionally, space and resources in a regular ambulance are limited. We have therefore developed a new protocol, covering the transport of critical care patients. In this, we use a special trolley with built-in advanced devices, such as a respiratory apparatus, in combination with an adapted ambulance. By using this protocol we minimize time loss and guarantee safe and patient-centred transport.

3D Imaging of a Dislocation Loop at the Onset of Plasticity in an Indented Nanocrystal

Structural quality and stability of nanocrystals are fundamental problems that bear important consequences for the performances of small-scale devices. Indeed, at the nanoscale, their functional properties are largely influenced by elastic strain and depend critically on the presence of crystal defects. It is thus of prime importance to be able to monitor, by noninvasive means, the stability of the microstructure of nano-objects against external stimuli such as mechanical load. Here we demonstrate the potential of Bragg coherent diffraction imaging for such measurements, by imaging in 3D the evolution of the microstructure of a nanocrystal exposed to in situ mechanical loading. Not only could we observe the evolution of the internal strain field after successive loadings, but we also evidenced a transient microstructure hosting a stable dislocation loop. The latter is fully characterized from its characteristic displacement field. The mechanical behavior of this small crystal is clearly at odds with what happens in bulk materials where many dislocations interact. Moreover, this original in situ experiment opens interesting possibilities for the investigation of plastic deformation at the nanoscale.

Reactor for nano-focused x-ray diffraction and imaging under catalytic in situ conditions

A reactor cell for in situ studies of individual catalyst nanoparticles or surfaces by nano-focused (coherent) x-ray diffraction has been developed. Catalytic reactions can be studied in flow mode in a pressure range of 10^-2-10³ mbar and temperatures up to 900 °C. This instrument bridges the pressure and materials gap at the same time within one experimental setup. It allows us to probe in situ the structure (e.g., shape, size, strain, faceting, composition, and defects) of individual nanoparticles using a nano-focused x-ray beam. Here, the setup was used to observe strain and facet evolution of individual model Pt catalysts during in situ experiments. It can be used for heating other (non-catalytically active) nanoparticles (e.g., nanowires) in inert or reactive gas atmospheres or vacuum as well.

A novel BCMA/CD3 bispecific T-cell engager for the treatment of multiple myeloma induces selective lysis in vitro and in vivo

This corrects the article DOI: 10.1038/leu.2016.388.

KB scanning of X-ray beam for Laue microdiffraction on accelero-phobic samples: application to in situ mechanically loaded nanowires

A mapping technique has been developed where a sub-micrometer focused polychromatic X-ray beam is scanned across a stationary sample instead of scanning the sample in front of the X-ray microbeam. This method is applied to a gold nanowire during its mechanical loading using the tip of an atomic force microscope. During the loading process, such a sample is `accelero-phobic', i.e. the sample scanning stages must not to be moved to avoid parasitic additional load. Without beam scanning, only one single position within the sample can be probed during the test. The probed material point may even change because of drifts or movements induced by the test itself. The new scanning approach facilitates the in situ mapping of the entire wire giving access to the evolution of the wire shape as well as to the boundary conditions. This novel scanning technique opens promising perspectives for studies where sample motion is forbidden because of the sample environment.

Effect of subthreshold slope on the sensitivity of nanoribbon sensors

In this work, we investigate how the sensitivity of a nanowire or nanoribbon sensor is influenced by the subthreshold slope of the sensing transistor. Polysilicon nanoribbon sensors are fabricated with a wide range of subthreshold slopes and the sensitivity is characterized using pH measurements. It is shown that there is a strong relationship between the sensitivity and the device subthreshold slope. The sensitivity is characterized using the current sensitivity per pH, which is shown to increase from 1.2% ph(-1) to 33.6% ph(-1) as the subthreshold slope improves from 6.2 V dec(-1) to 0.23 V dec(-1) respectively. We propose a model that relates current sensitivity per pH to the subthreshold slope of the sensing transistor. The model shows that sensitivity is determined only on the subthreshold slope of the sensing transistor and the choice of gate insulator. The model fully explains the values of current sensitivity per pH for the broad range of subthreshold slopes obtained in our fabricated nanoribbon devices. It is also able to explain values of sensitivity reported in the literature, which range from 2.5% pH(-1) to 650% pH(-1) for a variety of nanoribbon and nanowire sensors. Furthermore, it shows that aggressive device scaling is not the key to high sensitivity. For the first time, a figure-of-merit is proposed to compare the performance of nanoscale field effect transistor sensors fabricated using different materials and technologies.

Dual-gate polysilicon nanoribbon biosensors enable high sensitivity detection of proteins

We demonstrate the advantages of dual-gate polysilicon nanoribbon biosensors with a comprehensive evaluation of different measurement schemes for pH and protein sensing. In particular, we compare the detection of voltage and current changes when top- and bottom-gate bias is applied. Measurements of pH show that a large voltage shift of 491 mV pH(-1) is obtained in the subthreshold region when the top-gate is kept at a fixed potential and the bottom-gate is varied (voltage sweep). This is an improvement of 16 times over the 30 mV pH(-1) measured using a top-gate sweep with the bottom-gate at a fixed potential. A similar large voltage shift of 175 mV is obtained when the protein avidin is sensed using a bottom-gate sweep. This is an improvement of 20 times compared with the 8.8 mV achieved from a top-gate sweep. Current measurements using bottom-gate sweeps do not deliver the same signal amplification as when using bottom-gate sweeps to measure voltage shifts. Thus, for detecting a small signal change on protein binding, it is advantageous to employ a double-gate transistor and to measure a voltage shift using a bottom-gate sweep. For top-gate sweeps, the use of a dual-gate transistor enables the current sensitivity to be enhanced by applying a negative bias to the bottom-gate to reduce the carrier concentration in the nanoribbon. For pH measurements, the current sensitivity increases from 65% to 149% and for avidin sensing it increases from 1.4% to 2.5%.

Carbon Nanotube Interconnects Realized through Functionalization and Sintered Silver Attachment

Carbon nanotubes (CNTs) in the form of interconnects have many potential applications, and their ability to perform at high temperatures gives them a unique capability. We show the development of a novel transfer process using CNTs and sintered silver that offers a unique high-temperature, high-conductivity, and potentially flexible interconnect solution. Arrays of vertically aligned multiwalled carbon nanotubes of approximately 200 μm in length were grown on silicon substrates, using low-temperature photothermal chemical vapor deposition. Oxygen plasma treatment was used to introduce defects, in the form of hydroxyl, carbonyl, and carboxyl groups, on the walls of the carbon nanotubes so that they could bond to palladium (Pd). Nanoparticle silver was then used to bind the Pd-coated multiwalled CNTs to a copper substrate. The silver-CNT-silver interconnects were found to be ohmic conductors, with resistivity of 6.2 × 10(-4) Ωm; the interconnects were heated to temperatures exceeding 300 °C (where common solders fail) and were found to maintain their electrical performance.

Continuous and Collective Grain Rotation in Nanoscale Thin Films during Silicidation

Texture evolution is an important issue in materials and nanosciences. Understanding it is fundamental for controlling the final orientation, which in fine controls the desired properties of nanodevices. Here, we reveal the formation of a peculiar texture during the silicidation of nanoscale Pd thin films. We demonstrate that the crystallographic relationship observed between the silicide and the Si(001) substrate, named gyroaxy, evolves continuously and collectively during silicidation. This continuous rotation of the nanosized grains over a wide angular range is proposed to be associated with a diffusional mechanism.

Dilated perivascular spaces in the Basal Ganglia are a biomarker of small-vessel disease in a very elderly population with dementia

BACKGROUND AND PURPOSE

Dilated perivascular spaces have been shown to be a specific biomarker of cerebral small-vessel disease in young patients with dementia. Our aim was to examine the discriminative power of dilated cerebral perivascular spaces as biomarkers of small-vessel disease in a very elderly population of patients with dementia.

MATERIALS AND METHODS

We studied healthy volunteers (n = 65; mean age, 78 ± 5.6 years) and subjects with vascular dementia (n = 39; mean age, 76.9 ± 7.7 years) and Alzheimer disease (n = 47; mean age, 74.1 ± 8.5 years). We compared white matter hyperintensity and 2 semiquantitative perivascular space scoring systems (perivascular space-1 and perivascular space-2). Intra- and interobserver agreement was assessed by using a weighted Cohen κ statistic. Multinomial regression modeling was used to assess the discriminative power of imaging features to distinguish clinical groups.

RESULTS

White matter hyperintensity scores were higher in vascular dementia than in Alzheimer disease (P < .05) or healthy volunteers (P < .01). The perivascular space-1 score was higher in vascular dementia and Alzheimer disease than in healthy volunteers (P < .01). The perivascular space-2 score in the centrum semiovale showed no intergroup differences. However, perivascular space-2 in the basal ganglia was higher in vascular dementia than in Alzheimer disease (P < .05) or healthy volunteers (P < .001) and higher in Alzheimer disease than in healthy volunteers (P < .001). Modeling of dementia versus healthy volunteers, Alzheimer disease versus healthy volunteers, and vascular dementia against Alzheimer disease demonstrated perivascular space-2basal ganglia as the only imaging parameter with independent significant discriminative power (P < .01, P < .01, and P < .05) with areas under the receiver operating characteristic curve of 0.855, 0.774, and 0.71, respectively. Modeling of vascular dementia versus healthy volunteers showed that perivascular space-2basal ganglia (P < .01) and the modified Scheltens score (P < .05) contributed significant, independent discriminatory power, accounting for 34% and 13% of the variance in the model respectively.

CONCLUSIONS

Dilated perivascular spaces remain a valuable biomarker of small-vessel disease in an elderly population.

Mechanism of cytotoxic action of crambescidin-816 on human liver-derived tumour cells

BACKGROUND AND PURPOSE

Marine sponges have evolved the capacity to produce a series of very efficient chemicals to combat viruses, bacteria, and eukaryotic organisms. It has been demonstrated that several of these compounds have anti-neoplastic activity. The highly toxic sponge Crambe crambe has been the source of several molecules named crambescidins. Of these, crambescidin-816 has been shown to be cytotoxic for colon carcinoma cells. To further investigate the potential anti-carcinogenic effect of crambescidin-816, we analysed its effect on the transcription of HepG2 cells by microarray analysis followed by experiments guided by the results obtained.

EXPERIMENTAL APPROACH

After cytotoxicity determination, a transcriptomic analysis was performed to test the effect of crambescidin-816 on the liver-derived tumour cell HepG2. Based on the results obtained, we analysed the effect of crambescidin-816 on cell-cell adhesion, cell-matrix adhesion, and cell migration by Western blot, confocal microscopy, flow cytometry and transmission electron microscopy. Cytotoxicity and cell migration were also studied in a variety of other cell lines derived from human tumours.

KEY RESULTS

Crambescidin-816 had a cytotoxic effect on all the cell lines studied. It inhibited cell-cell adhesion, interfered with the formation of tight junctions, and cell-matrix adhesion, negatively affecting focal adhesions. It also altered the cytoskeleton dynamics. As a consequence of all these effects on cells crambescidin-816 inhibited cell migration.

CONCLUSIONS AND IMPLICATIONS

The results indicate that crambescidin-816 is active against tumour cells and implicate a new mechanism for the anti-tumour effect of this compound.

Retrieval of the atomic displacements in the crystal from the coherent X-ray diffraction pattern

The retrieval of spatially resolved atomic displacements is investigated via the phases of the direct(real)-space image reconstructed from the strained crystal's coherent X-ray diffraction pattern. It is demonstrated that limiting the spatial variation of the first- and second-order spatial displacement derivatives improves convergence of the iterative phase-retrieval algorithm for displacements reconstructions to the true solution. This approach is exploited to retrieve the displacement in a periodic array of silicon lines isolated by silicon dioxide filled trenches.

Revealing organic carbon-nitrate linear relationship from UV spectra of freshwaters in agricultural environment

A strong non linear relationship between nitrate and organic matter (assessed by dissolved organic carbon, DOC) has been recently demonstrated by Taylor and Townsend (2010), namely for freshwaters. In this context, our study explores this relation from the behavior of sets of normalized UV spectra (same area under each spectrum) of different water samples showing a hidden isosbestic point (HIP) around 225 nm. This HIP is linked to the existence of a simple relation between nitrate and DOC, the proportions of which vary according to the sampling location and environmental factors. In a second step, a simple linear model is proposed for nitrate-DOC relationship (α⋅NO3+β⋅DOC=1) and a validation is proposed for more than 150 samples of different Brittany rivers and lakes. For samples of the largest watershed, a complementary exploitation from data acquired during the different campaigns confirmed the seasonal evolution between spring (high nitrate/low DOC) and autumn (high DOC/low nitrate). Further investigation on other freshwater samples is needed in order to improve the limits of this linear model.

Monitoring of methotrexate chlorination in water

Anti-cancer drugs are an important class of pharmaceutical products. Methotrexate (MTX) is a folic acid antagonist used in high doses as antimetabolite in anti-cancer treatment as well as in low doses for the treatment of rheumatoid arthritis and adults' psoriasis. In the past, several anti-cancer drugs, including methotrexate, have been found in the environment. Their presence in water, especially if used for the production of drinking water, is even in low concentrations of particular interest, due to the risk to retrieve them in the consumed water and their high activity and grave effects. But prior to usage as drinking water, raw waters are treated and chlorination is a common practice in several countries. As such a treatment can lead to the formation of organochlorine in water, the study of the fate of MTX during chlorination in a batch trial was carried out. The reaction was monitored by dissolved organic carbon (DOC) and by fluorescence and UV spectroscopy. Investigation of by-products formed was done with liquid chromatography/mass spectrometry (LC/MS). Under the given experimental conditions, Methotrexate was eliminated rapidly (t1/2 around 21 min). However, DOC elimination was incomplete. Monitoring with LC-MS showed the formation of a monochlorinated transformation product of MTX. In silico analysis of the proposed transformation products for different carcinogenic, mutagenic and genotoxic endpoints with different software platforms provided no clear evidence that the possible transformation products after chlorination might be more toxic than the parent compound. However, since a number of alerts is altered after chlorination, it cannot be excluded that the toxicity of these transformation products might be modulated compared with the parent compound.

Pattern and predictors of volumetric change of parotid glands during intensity modulated radiotherapy

OBJECTIVE

To describe the pattern and predictors of volumetric change of parotid glands during intensity modulated radiotherapy (IMRT) for oropharyngeal cancer.

METHODS

A cohort of patients undergoing weekly CT scans during dose-painted IMRT was considered. The parotid glands were contoured at the time of treatment planning (baseline) and on all subsequent scans. For a given patient, the parotid glands were labelled as higher (H) and lower (L), based on the mean dose at planning. The volume of each gland was determined for each scan and the percent change from baseline computed. Data were fit to both linear and quadratic functions. The role of selected covariates was assessed with both logistic regression and pair-wise comparison between the sides. The analyses were performed considering the whole treatment duration or each separate half.

RESULTS

85 patients, 170 glands and 565 scans were analysed. For all parotids except one, the quadratic function provided a better fit than the linear one. Moreover, according to both the logistic regression and pair-wise comparison, the cumulative mean dose of radiation is independently correlated with the parotid shrinkage during the first but not the second half of the treatment. Conversely, age and weight loss are predictors of relative parotid shrinkage during the entire course of the treatment.

CONCLUSION

Parotid gland shrinkage during IMRT is not linear. Age, weight loss and radiation dose independently predict parotid shrinkage during a course of IMRT.

ADVANCES IN KNOWLEDGE

The present study adds to the pathophysiology of parotid shrinkage during radiotherapy.

In situ three-dimensional reciprocal-space mapping during mechanical deformation

Mechanical deformation of a SiGe island epitaxically grown on Si(001) was studied by a specially adapted atomic force microscope and nanofocused X-ray diffraction. The deformation was monitored during in situ mechanical loading by recording three-dimensional reciprocal-space maps around a selected Bragg peak. Scanning the energy of the incident beam instead of rocking the sample allowed the safe and reliable measurement of the reciprocal-space maps without removal of the mechanical load. The crystal truncation rods originating from the island side facets rotate to steeper angles with increasing mechanical load. Simulations of the displacement field and the intensity distribution, based on the finite-element method, reveal that the change in orientation of the side facets of about 25° corresponds to an applied pressure of 2-3 GPa on the island top plane.