Reduced Fractionation in Lung Cancer Patients Treated with Curative-intent Radiotherapy during the COVID-19 Pandemic.

Patients treated with curative-intent lung radiotherapy are in the group at highest risk of severe complications and death from COVID-19. There is therefore an urgent need to reduce the risks associated with multiple hospital visits and their anti-cancer treatment. One recommendation is to consider alternative dose-fractionation schedules or radiotherapy techniques. This would also increase radiotherapy service capacity for operable patients with stage I-III lung cancer, who might be unable to have surgery during the pandemic. Here we identify reduced-fractionation for curative-intent radiotherapy regimes in lung cancer, from a literature search carried out between 20/03/2020 and 30/03/2020 as well as published and unpublished audits of hypofractionated regimes from UK centres. Evidence, practical considerations and limitations are discussed for early-stage NSCLC, stage III NSCLC, early-stage and locally advanced SCLC. We recommend discussion of this guidance document with other specialist lung MDT members to disseminate the potential changes to radiotherapy practices that could be made to reduce pressure on other departments such as thoracic surgery. It is also a crucial part of the consent process to ensure that the risks and benefits of undergoing cancer treatment during the COVID-19 pandemic and the uncertainties surrounding toxicity from reduced fractionation have been adequately discussed with patients. Furthermore, centres should document all deviations from standard protocols, and we urge all colleagues, where possible, to join national/international data collection initiatives (such as COVID-RT Lung) aimed at recording the impact of the COVID-19 pandemic on lung cancer treatment and outcomes.

Strain-induced bi-thermoelectricity in tapered carbon nanotubes.

We show that carbon-based nanostructured materials are a novel testbed for controlling thermoelectricity and have the potential to underpin the development of new cost-effective environmentally-friendly thermoelectric materials. In single-molecule junctions, it is known that transport resonances associated with the discrete molecular levels play a key role in the thermoelectric performance, but such resonances have not been exploited in carbon nanotubes (CNTs). Here we study junctions formed from tapered CNTs and demonstrate that such structures possess transport resonances near the Fermi level, whose energetic location can be varied by applying strain, resulting in an ability to tune the sign of their Seebeck coefficient. These results reveal that tapered CNTs form a new class of bi-thermoelectric materials, exhibiting both positive and negative thermopower. This ability to change the sign of the Seebeck coefficient allows the thermovoltage in carbon-based thermoelectric devices to be boosted by placing CNTs with alternating-sign Seebeck coefficients in tandem.

Zone-Folded Phonons and the Commensurate-Incommensurate Charge-Density-Wave Transition in 1T-TaSe2 Thin Films.

Bulk 1T-TaSe2 exhibits unusually high charge density wave (CDW) transition temperatures of 600 and 473 K below which the material exists in the incommensurate (I-CDW) and the commensurate (C-CDW) charge-density-wave phases, respectively. The (13)(1/2) × (13)(1/2) C-CDW reconstruction of the lattice coincides with new Raman peaks resulting from zone-folding of phonon modes from middle regions of the original Brillouin zone back to Γ. The C-CDW transition temperatures as a function of film thickness are determined from the evolution of these new Raman peaks, and they are found to decrease from 473 to 413 K as the film thicknesses decrease from 150 to 35 nm. A comparison of the Raman data with ab initio calculations of both the normal and C-CDW phases gives a consistent picture of the zone-folding of the phonon modes following lattice reconstruction. The Raman peak at ∼154 cm(-1) originates from the zone-folded phonons in the C-CDW phase. In the I-CDW phase, the loss of translational symmetry coincides with a strong suppression and broadening of the Raman peaks. The observed change in the C-CDW transition temperature is consistent with total energy calculations of bulk and monolayer 1T-TaSe2.

Graphene sculpturene nanopores for DNA nucleobase sensing.

To demonstrate the potential of nanopores in bilayer graphene for DNA sequencing, we computed the current-voltage characteristics of a bilayer graphene junction containing a nanopore and found that they change significantly when nucleobases are transported through the pore. To demonstrate the sensitivity and selectivity of example devices, we computed the probability distribution PX(ß) of the quantity ß representing the change in the logarithmic current through the pore due to the presence of a nucleobase X (X = adenine, thymine, guanine, or cytosine). We quantified the selectivity of the bilayer-graphene nanopores by showing that PX(ß) exhibits distinct peaks for each base X. To demonstrate that such discriminating sensing is a general feature of bilayer nanopores, the well-separated positions of these peaks were shown to be present for different pores, with alternative examples of electrical contacts.

Treating hop plants with (Z)-jasmone increases colonization by Phorodon humuli (Hemiptera: Aphididae) spring migrants.

Hop plants were sprayed with (Z)-jasmone, at a rate of 50 g ha(-1), during the spring migration of the damson-hop aphid Phorodon humuli (Schrank) in 2002 and 2003. Numbers of P. humuli spring migrants colonizing hop plants, Humulus lupulus L., 2-6 and 7-11 days after applying this treatment were assessed in both years. During the first five-day period, significantly more spring migrants were found on hop plants treated with (Z)-jasmone, in comparison with control plants, in 2002. By contrast, no significant difference was evident in the second five-day period. Although the migration in 2003 was much lighter than in 2002, greater numbers of migrants were again removed from treated plants. Indeed, more spring migrants were removed from plants sprayed with (Z)-jasmone in this year during both five-day periods (11 and 44%, respectively) compared with the 23% greater numbers removed in the first five-day period in 2002. Therefore, unlike some other species of aphid, where numbers were consistently lower on plots sprayed with (Z)-jasmone, spraying the secondary host of P. humuli with this compound appears to increase colonization by spring migrants.

Polymorphism of visual pigment genes in the muriqui (Primates, Atelidae).

Colour vision varies within the family Atelidae (Primates, Platyrrhini), which consists of four genera with the following cladistic relationship: {Alouatta[Ateles (Lagothrix and Brachyteles)]}. Spider monkeys (Ateles) and woolly monkeys (Lagothrix) are characteristic of platyrrhine monkeys in possessing a colour vision polymorphism. The polymorphism results from allelic variation of the single-locus middle-to-long wavelength (M/L) cone opsin gene on the X-chromosome. The presence in the population of alleles coding for different M/L photopigments results in a variety of colour vision phenotypes. Such a polymorphism is absent in howling monkeys (Alouatta), which, alone among platyrrhines, acquired uniform trichromatic vision similar to that of Old World monkeys, apes, and humans through opsin gene duplication. Dietary and morphological similarities between howling monkeys and muriquis (Brachyteles) raise the possibility that the two genera share a similar form of colour vision, uniform trichromacy. Yet parsimony predicts that the colour vision of Brachyteles will resemble the polymorphism present in Lagothrix and Ateles. Here we test this assumption. We obtained DNA from the blood or faeces of 18 muriquis and sequenced exons 3 and 5 of the M/L opsin gene. Our results affirm the existence of a single M/L cone opsin gene in the genus Brachyteles. We detected three alleles with predicted lambdamax values of 530, 550, and 562 nm. Two females were heterozygous and are thus predicted to have different types of M/L cone pigment. We discuss the implication of this result towards understanding the evolutionary ecology of trichromatic vision.

Growth performance and nitrogen excretion of broilers using a phase-feeding approach from twenty-one to sixty-three days of age.

Two experiments were conducted to assess effects of phase-feeding (PF) on broilers from 21 to 63 d. Experiment 1 evaluated the impact of PF on growth performance, whereas experiment 2 assessed the effects of PF on CP intake and nitrogen excretion. Diets were formulated using recommendations from NRC or linear regression equations. Two PF treatments were prepared: standard (PF) and low (PF10), in which predicted Lys, sulfur amino acid, and Thr recommendations were reduced by 10%. For PF and PF10, 2 diets (high-nutrient and low-nutrient density) were blended in variable quantities to produce rations matching predicted requirements. An NRC grower and finisher diet or a series of PF and PF10 diets that were switched every other day were fed. In experiment 1, weight gain and feed efficiency were improved (P < 0.05) by PF10 relative to broilers fed the NRC-based diet. Crude protein intake was reduced (P < 0.05) by PF10 relative to broilers fed NRC and PF diets. No differences (P > 0.05) in percentage carcass composition were observed when broilers were fed PF or PF10 diets. Significant reductions (P < 0.05) in dollars per kilogram of weight gain were noted with PF regimens. In experiment 2, PF and PF10 diets reduced (P < 0.05) CP intake and nitrogen excretion from 43 to 63 d. Results indicate that PF regimens may substantially reduce dietary costs and may have environmental benefits.

Growth performance of broilers using a phase-feeding approach with diets switched every other day from forty-two to sixty-three days of age.

Phase-feeding (PF; Treatment 2) was tested relative to an NRC regimen (Treatment 1) to evaluate the impact of PF on broilers during the finisher period (42 to 63 d). Two modified PF treatments were also tested during this experiment: Treatment 3 involved lowering the amino acid requirements predicted with PF linear regression equations by 10% (PF10), Treatment 4 involved increasing the slope of the linear regression equations by 15% (PF15). Broilers fed Treatment 1 consumed a single diet throughout the experiment, whereas PF treatments were fed in a series of 11 diets in which feed was switched every other day, resulting in steadily decreasing lysine, SAA, and threonine levels. On Day 63, weight gain, feed intake, feed efficiency, and crude protein intake did not differ (P > 0.05) among birds fed PF treatments and Treatment 1. Digestible lysine and threonine intakes were increased (P < 0.05) for Treatment 1 relative to the PF treatments, and digestible SAA intake for the NRC treatment was increased (P < 0.05) relative to the PF10 and PF15 treatments. Compared to Treatment 1, no differences (P > 0.05) in percentage breast, wing, leg, or abdominal fat were observed when birds were fed PF, PF10, or PF15 diets. These results indicate that PF supports maximum growth performance during an extended finisher period, even when lysine, SAA, and threonine levels are reduced every other day. Economic analysis indicated that PF regimens may lead to savings ($ per kg weight gain or breast meat).

Impact of phase-feeding on the growth performance of broilers subjected to high environmental temperatures.

Experiments were conducted to evaluate the effects of phase feeding (PF) on broilers subjected to heat stress during the grower and finisher periods. Birds were fed diets containing lysine, sulfur amino acid (SAA), or threonine levels based on NRC (1994) recommendations or predictions from linear regression equations (PF). With PF, diets were switched every other day, resulting in steadily decreasing lysine, SAA, and threonine levels. In Experiment 1 (42 to 56 d), growth performance was unaffected (P > 0.05) by diet, and cost per kilogram of weight gain did not differ (P > 0.05) between treatments. In Experiments 2 (23 to 42 d) and 3 (42 to 63 d) birds were housed in environmental chambers and subjected to high (15 h at 35 C, 9 h at 23.9 C) or normal (23.9 C) temperatures. In both experiments, heat stress reduced (P < 0.05) growth performance and increased (P < 0.05) percentage leg yield. Moreover, heat stress decreased percentage breast yield (P < 0.05) in Experiment 2. Growth performance and carcass yield were unaffected (P > 0.05) by PF relative to birds fed NRC-based diets, with the exception of feed efficiency, which was reduced (P < 0.05) by PF under normal temperatures in Experiment 2. Data indicated that dietary lysine, SAA, and threonine levels may be reduced every other day under a PF program without adversely affecting growth performance or carcass yield of birds exposed to high environmental temperatures. Cost analysis indicated that savings might be available with PF under high temperature conditions.

MR imaging of patellar dislocation and relocation.

Patellar dislocation and relocation (PDR) typically occurs suddenly after trauma or torsional stress on the extensor mechanism. Clinical evaluation after patellar dislocation/relocation usually reveals a swollen knee that is difficult to examine. Radiographs may show hemathroses and a minority of patients will have a chip fracture of the patella. Magnetic resonance (MR) imaging features seen with PDR include disruption or sprain of the medial retinaculum, lateral patellar tilt or subluxation, lateral femoral condylar and medical patellar osseous contusions, osteochondral injury, damage to Hoffa's fat pad, and joint effusion. Up to one third of patients will also show concomitant injury to the major ligaments of the knee or menisci. Without repair of the primary injury, redislocation occurs in greater than one half of patients. Consequently, surgical correction is often advocated. This article reviews the factors predisposing to PDR, the activities associated with PDR, the clinical, radiographic, and MR imaging features of PDR, and (briefly) therapy for this injury.

The role of hip arthroscopy in the evaluation of avascular necrosis.

This prospective study evaluated the correlation between plain radiographs, magnetic resonance imaging (MRI), and diagnostic arthroscopy in the staging of avascular necrosis of the femoral head. Fifty-two hips in 46 patients were prospectively staged using radiographic and MRI staging systems. Patients subsequently underwent hip arthroscopy to visualize the articular surface prior to considering salvage of the femoral head and debride delaminated osteochondral fragments. Weighted Kappa analysis revealed only moderate correlation between MRI and plain radiographs (K=.11), MRI and arthroscopy (K=.21), and plain radiographs and arthroscopy (K=.19). Six (46%) of 13 patients with a radiographically apparent subchondral fracture demonstrated collapse of the articular surface at arthroscopy. Four (24%) of 17 hips with >2 mm of collapse of the femoral head on plain radiographs demonstrated fragmentation of the osteochondral surface of the femoral head at arthroscopy. In 5 patients with flattening of the femoral head, 3 patients had delamination of both the femoral and acetabular surfaces. In regard to labral pathology, 5 of 22 post-collapse hips also had large bucket handle tears of the labrum. Arthroscopy of the hip revealed osteochondral degeneration that was not detected by plain radiographs or MRI in 36% of post-collapse femoral heads.

Neurologic dysfunction in patients with rheumatoid arthritis of the cervical spine. Predictive value of clinical, radiographic and MR imaging parameters.

The aim of this study was to evaluate if subjective symptoms, radiographic and especially MR parameters of cervical spine involvement, can predict neurologic dysfunction in patients with severe rheumatoid arthritis (RA). Sequential radiographs, MR imaging, and neurologic examination were performed yearly in 46 consecutive RA patients with symptoms indicative of cervical spine involvement. Radiographic parameters were erosions of the dens or intervertebral joints, disc-space narrowing, horizontal and vertical atlantoaxial subluxation, subluxations below C2, and the diameter of the spinal canal. The MR features evaluated were presence of dens and atlas erosion, brainstem compression, subarachnoid space encroachment, pannus around the dens, abnormal fat body caudal to the clivus, cervicomedullary angle, and distance of the dens to the line of McRae. Muscle weakness was associated with a tenfold increased risk of neurologic dysfunction. Radiographic parameters were not associated. On MR images atlas erosion and a decreased distance of the dens to the line of McRae showed a fivefold increased risk of neurologic dysfunction. Subarachnoid space encroachment was associated with a 12-fold increased risk. Rheumatoid arthritis patients with muscle weakness and subarachnoid space encroachment of the entire cervical spine have a highly increased risk of developing neurologic dysfunction.

Phase-feeding supports maximum growth performance of broiler chicks from forty-three to seventy-one days of age.

Phase-feeding (PF) was tested to evaluate its efficacy compared with NRC recommendations for broilers. Two modified PF regimens were also tested that involved lowering amino acid requirements predicted by PF linear regression equations by 10% (PF10) and increasing the slope of the linear regression equations by 15% (PF15). Experimental diets were fed from 43 to 71 d. Broilers fed the NRC regimen were given a single diet throughout the experiment, whereas PF, PF10, and PF15 were tested with a series of four diets (43 to 50 d, 50 to 57 d, 57 to 64 d, and 64 to 71 d). At 71 d, no differences (P < 0.05) in weight gain, feed intake, or feed efficiency were observed among treatments. Intake of crude protein, digestible lysine, sulfur amino acids (SAA), and threonine were decreased (P < 0.05) by PF, PF10, and PF15 relative to that of broilers fed the NRC diet. Gain per unit digestible lysine and threonine intake were increased (P < 0.05) by PF, PF10, and PF15, and gain per unit digestible SAA intake was increased (P < 0.05) by PF10 and PF15 relative to broilers fed the NRC diet. No differences (P > 0.05) were observed in carcass, breast, wing, or leg yield, but abdominal fat was increased (P < 0.05) by the PF10 regimen relative to that of broilers fed the NRC diet. Economic analysis indicated that PF and PF10 may lower the cost of feed consumed and the cost per unit weight gain or breast yield relative to broilers fed the NRC diet.

Are magnetic resonance flexion views useful in evaluating the cervical spine of patients with rheumatoid arthritis?

OBJECTIVE: To determine whether MR imaging in flexion adds value relative to imaging in the neutral position with respect to displaying involvement of the subarachnoid space, brainstem and spinal cord. DESIGN AND PATIENTS: T1-weighted MR images of the cervical spine in 42 rheumatoid arthritis patients with cervical spine involvement were obtained and analyzed prospectively. We assessed changes between images obtained in the neutral position and following active flexion, especially horizontal atlantoaxial and subaxial motion, presence or absence of brainstem compression, subarachnoid space involvement at the atlantoaxial and subaxial level and the cervicomedullary angle. Vertical atlantoaxial subluxation and the amount of pannus were correlated with motion and change in subarachnoid space. RESULTS: The flexion images showed horizontal atlantoaxial motion in 21 patients and subaxial motion in one patient. The flexion view displayed brainstem compression in only one patient. Involvement of the subarachnoid space increased at the atlantoaxial level in eight (19%) patients (P=0.004) and at the level below C2 in five (12%) patients (P=0.03). There were no patients with a normal subarachnoid space in neutral position and compression in the flexed position. The cervicomedullary angle changed significantly with flexion. Vertical atlantoaxial subluxation and the amount of pannus did not show a significant correlation with motion or subarachnoid space involvement. CONCLUSION: MR imaging in the flexed position shows a statistically significant narrowing of the subarachnoid space at the atlantoaxial level and below C2. Cord compression is only observed on flexion views if the subarachnoid space in neutral position is already decreased. MR imaging in the flexed position might be useful, since subarachnoid space involvement may be an indicator for the development of neurologic dysfunction.

Hip arthroscopy in staging avascular necrosis of the femoral head.

The purposes of this study were to evaluate how accurately current imaging modalities predict the quality of the articular surface in avascular necrosis (AVN) of the femoral head and to provide arthroscopic correlation to current staging modalities. An arthroscopic classification system, derived from the work of Marcus et al, was used to prospectively stage the articular surface in 23 hips with AVN using plain radiographs, magnetic resonance imaging (MRI), and arthroscopy. There was little correlation between all three diagnostic modalities. These findings were not statistically significant. Patients with stage IV disease had the widest variation in the appearance of the articular surface. This study shows poor correlation in the staging of AVN using current imaging techniques. Magnetic resonance imaging has been shown to be inadequate at assessing the articular cartilage. Therefore, either arthroscopy or direct visualization is required for accurate evaluation and staging, especially in stage IV disease.