To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure firstname.lastname@example.org
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
During the radiation therapy of tumoral breast, the contralateral breast (CB) will receive scattered doses. In the present study, the photon and thermal neutron dose values received by CB surface during breast cancer radiation therapy were measured.
Materials and methods:
The right breast region of RANDO phantom was considered as CB, and the measurements of photon and thermal neutron dose values were carried out on this region surface. The phantom was irradiated with 18 MV photon beams, and the dose values were measured with thermoluminescent dosimeter (TLD-600 and TLD-700) chips for 11 × 13, 11 × 17 and 11 × 21 cm2 field sizes in the presence of physical and dynamic wedges.
The total dose values (photon + thermal neutron) received by the CB surface in the presence of physical wedge were 12·06%, 15·75% and 33·40% of the prescribed dose, respectively, for 11 × 13, 11 × 17 and 11 × 21 cm2 field sizes. The corresponding dose values for dynamic wedge were 9·18%, 12·92% and 29·26% of the prescribed dose, respectively. Moreover, the results showed that treatment field size and wedge type affect the received photon and thermal neutron doses at CB surface.
According to our results, the total dose values received at CB surface during breast cancer radiotherapy with high-energy photon beams are remarkable. In addition, the dose values received at CB surface when using a physical wedge were greater than when using a dynamic wedge, especially for medial tangential fields.
The main objective of this study is to assure the quality of cervical cancer treatment plans using an electronic portal imaging device (EPID) in RapidArc techniques.
Materials and Methods:
Fifteen cases of cervical cancer patients undergoing RapidArc technique were selected to evaluate the quality assurance (QA) of their treatment. The computed tomography (CT) of each patient was obtained with 3-mm-slice thickness and transferred to the Eclipse treatment planning system. The prescribed dose (PD) of 50·4 Gy with 1·8 Gy per fraction to planning target volume (PTV) was used for each patient. The aim of treatment planning was to achieve 95% of PD to cover 97%, and dose to the PTV should not receive 105% of the PD. All RapidArc plans were created using the AAA algorithm and treated on Varian DHX using 6 MV photon beam, with two full arcs. Gamma analysis was used to evaluate the quality of the treatment plans with accepting criteria of 95% at 3%/3 mm.
In this study, maximum and average gamma values were 2·53 ± 0·409 and 0·195 ± 0·059 showing very small deviation and indicating the smaller difference between both predicted and portal doses. Gamma Area changes from > 0·8 to > 1·2. SD increased to 5·4% and mean standard error increased to 4·67%.
On the basis of these outcomes, we can summarise that the EPID is a useful tool for QA in standardising and evaluating RapidArc treatment plans of cervical cancer in routine clinical practice.
This paper concerns with comparing simulation studies for a newly developed concept of turning point to be used in multiple robot path planning. Different critical factors and design parameters are collected and statistical analyses are performed. After configuring different simulation scenarios, the efficient one is evaluated using a robust data envelopment analysis (RDEA). Due to uncertain aspects of various simulations scenarios, robust version of data envelopment analysis is proposed. Here, major criteria in robot path planning are deadlock and conflict avoidance, throughput, mean flow time, and effective total distance travelled. To determine the effective experiment for the proposed simulation model, RDEA is used. A comparative study with respect to different experiments having various simulation setting is developed. The results for a real robotic manufacturing cell system show effectiveness of the proposed process. Also, the efficient simulation software is determined by multiaspect analysis.
Smithian–lower Anisian strata in Peary Land, North Greenland, were deposited at ∼45° N on the northern margin of Pangaea in offshore to upper shoreface settings. The well-constrained succession (palynology and ammonite biostratigraphy) documents a remarkable shift from lycophyte spore-dominated assemblages in the upper Smithian to gymnosperm pollen-dominated ones in the lower Spathian in concert with a marked shift of +6 ‰ in δ13Corg. Correlation with other Smithian–Spathian boundary sections that record terrestrial floral changes indicates that the recovery of gymnosperms began earlier in the mid-latitudes of the Southern Hemisphere than in the Northern Hemisphere. The lycophyte-dominated Late Smithian Thermal Maximum is here interpreted as reflecting dry and hot climatic conditions with only brief seasonal precipitation unable to sustain large areas of gymnosperm trees, but able to revive dehydrated lycophytes. This suggests that the Late Smithian Thermal Maximum was a time of widespread aridity, which is also supported by red bed deposition in many areas globally, even as far south as Antarctica. The shift to gymnosperm-dominated vegetation during the cooling across the Smithian–Spathian boundary reflects a change to seasonally more humid climatic conditions favouring gymnosperm recovery, and could have been initiated by increased albedo over land due to the widespread aridity during the Late Smithian Thermal Maximum. The recovery of gymnosperm vegetation would have helped to draw down CO2 from the atmosphere and exacerbate global cooling.
The world has the largest number of refugees and asylum seekers living outside their country of origin due to wars, political upheavals, violence and various other causes than there have been at any time since World War II. This crisis has an impact on all services in countries that are hosting refugees. Most research has focused on the needs of younger refugees and women and has neglected to study older individuals and their particular vulnerabilities.
Recent studies have increasingly suggested leadership as a major antecedent to corporate social responsibility (CSR), empirical studies, which investigated the influence of various leadership aspects such as style and ethics on CSR and unraveled the mechanism through which leadership exerts its impact on CSR were restricted. Thus, the purpose of this research was to study the relationship between CEO ethical leadership and CSR by focusing on the mediating role of ethical culture and the intellectual capital facets (human capital and social capital) of the organization. Data for current research were collected through personally administered questionnaire through survey. Based on a sample of 250 respondents, the current study instituted that CEO ethical leadership positively affected CSR. Intellectual capital facets (human and social) and organizational ethical culture were observed to have a mediating effect on CEO ethical leadership and CSR relationship. Practical implications of the results are also given in the current study. Moreover, study limitations and directions for future study have also been presented.
The service user experience of children, their families and other stakeholders in a therapeutic program should inform quality of care, practice and organisation of services. Children referred to Take Two are clients of Child Protection for whom abuse and neglect have been substantiated. This paper aims to describe the development of the Take Two Stakeholder Survey, as well as to examine the reliability and factorial structure of the survey. In addition, the experience of consumers utilising the service will be described together with recommendations for clinical practice improvements and enhanced consumer engagement.
In this paper, a microstrip lowpass filter using rectangular resonators is designed. To weaken the undesired harmonics from 10 to 20 GHz, a stair-shaped suppressing cell and also high impedance elements at the edges are utilized. It should be noted that for analyzing the proposed filter, an LC model is used and the design is done in such a way that the coupling effects of the close-up lines are reduced as much as possible, so that they are ignored in the circuit analysis. The designed filter has a cut-off frequency of 1.01 GHz and the transition band is only 0.1 GHz. In addition to compression of dimensions, the stopband bandwidth is 18.7 times the cut-off frequency (18.7 × fc). The attenuation rate in the passband reaches 0.081 dB which indicates that the passband is flat. In the stopband, disturbing harmonics have been dampened to −23.5 dB and a good bandwidth is achieved. The figure of merit of the proposed filter is 180 387 and it is a good benchmark for the overall comparison of the proposed filter with the previous works.
The relationship between alcohol and other drugs (AOD) misuse and intimate partner violence (IPV) is well established. However, there is a pressing need for knowledge translation in relation to the association between AOD, IPV and child abuse and neglect. A substantial number of research studies and literature reviews on the relationship between AOD and IPV have appeared over the past several decades. However, heterogeneity across the literature reviews and findings, as well as in methodological differences and limitations, may contribute to interpretive difficulties that confound conclusions and/or create confusion among the researchers, practitioners and policy makers who turn to this literature for guidance in their research, treatment and policy decisions. To address this issue, this paper examines the evidence on the topic of AOD and IPV through a focused review-of-reviews methodology to compare and synthesise the overall patterns of findings derived from several reviews that have investigated the literature on the relationship between AOD and IPV. The results derived from the review-of-reviews are synthesised and integrated to present an understanding of the association between AOD and IPV in reference to child abuse and neglect. The limitations for research and practice are discussed, placing particular focus on knowledge translation in relation to child welfare policy and parents and children involved with child protection authorities.
To investigate the expression of basic fibroblast growth factor in the matrix of human acquired cholesteatoma compared to the deep meatal skin. This topic does not appear to have been fully investigated before.
An immunochemical study was conducted. Cholesteatoma tissues from adult patients were collected during surgery (n = 19). Control specimens were taken from the deep meatal skin (n = 8) and compared.
A highly significant difference in basic fibroblast growth factor expression was identified between cholesteatoma and skin (mean ± standard error = 58.53 ± 3.6 per cent in cholesteatoma vs 40.6 ± 3.5 per cent in skin; p = 0.005). Both basal and parabasal keratinocytes were stained positive with basic fibroblast growth factor. Additionally, there was specific staining in the basal columnar middle-ear epithelium and mast cell membrane.
Basic fibroblast growth factor plays an active role in proliferative activity of cholesteatoma through its overexpression in basal and parabasal layers of cholesteatoma matrix. Moreover, its expression in the mast cell membrane supports its role in bone resorption activity.
Sol–gel spin coating is applied to fabricate the pure and different concentrations of aluminum (Al)-doped ZnO films on high-quality silicon substrates. All films are showing high crystallinity in X-ray diffraction study, and lattice constants were obtained using PowderX software. The value of crystallite size was found in range of 20–40 nm. EDX/SEM mapping was performed for 2 wt% Al-doped ZnO film, which shows the presence of Al and its homogeneous distribution in the film. SEM investigation shows nanorods morphology all over the surface of films, and the dimension of nanorods is found to increase with Al doping. The E(g)dire. values were estimate in range of 3.25–3.29 eV for all films. Linear refractive index was found in range of 1.5–2.75. The χ1 value is found in range of 0.13–1.4 for all films. The χ3 values are found in range of 0.0053 × 10−10 to 6.24 × 10−10 esu for pure and doped films. The n2 values were also estimated. These studies clearly showed that the properties of ZnO have been enriched by Al doping, and hence doped films are more appropriate for optoelectronic applications.
The high prevalence, disability, and work absenteeism associated with back pain make it the single most costly musculoskeletal health condition in developed countries. However, the majority of back pain has no identifiable pathological cause and resolves without surgery or imaging. This paradox suggests that we need to change how back pain is managed to reduce unnecessary burden to individuals and the healthcare system. This study evaluated the cost of a new model of early triage-based, interprofessional care for patients with back pain.
We evaluated the outcomes and cost of implementing a provincial care pathway for early assessment of patients with back pain at three sites: (i) adjacent to an emergency department in a community hospital; (ii) co-located with an orthopedic surgeon's clinic in a hospital; and (iii) in a primary care network (PCN) with private practice physiotherapists and chiropractors. Time-driven activity-based costing (TDABC), in combination with discrete event simulation, was used to estimate costs.
Costs were significantly lower in the models that used hospital-based physiotherapists and in the PCN model that used private practice physiotherapists and chiropractors to triage patients. These costs ranged from CAD 20 (USD 16) to manage patients identified with low severity back pain to CAD 175 to 200 (USD 137 to 156) for those with moderate to severe back pain. Models that implemented the care pathway using family physicians and surgeons to review non-surgical patients were more expensive at CAD 339 (USD 265) and CAD 514 (USD 402), respectively.
New models of care that use the skills of physiotherapists and chiropractors to assess and triage patients with back pain adjacent to emergency departments and in the primary care sector are cost effective, compared with traditional physician-led models. The overarching intent is to use these data to enable evidence-informed policy and practice changes, so that more appropriate and cost-effective care is provided to patients with back pain.
In this paper, a high-gain dual-band distributed amplifier (DBDA) based on the metamaterial transmission line (TL) is proposed. To have two separate frequency bands in the distributed amplifiers, the composite right/left-handed (CRLH) TLs are used instead of conventional TLs. Although both forward and reverse gains of the distributed amplifiers are available in this case, they suffer from their low gains. In this paper, to increase the DBDA power gain, a new circuit architecture for the CRLH TL is introduced. By using the proposed CRLH TL, a lower wave attenuation coefficient at the forward band of the DBDA is achieved than the conventional structures, which causes a higher forward power gain. Simulation results also show that the power gain of the proposed DBDA is about 28.5 dB at the desired frequency bands, and good agreement between the measurement and simulation results confirms the accuracy of the design method.
Based on the conservation of resource theory, this study investigated a moderated mediation model in which perceived co-worker support moderated the mediation of supervisory feedback avoidance between abusive supervision and help-seeking behaviour. Data from matching dyads of 220 house officers and 86 postgraduate medical staff were collected from several hospitals in Pakistan. Results of hierarchical multiple regression analyses supported the hypothesized model that abusive supervision first positively led to supervisory feedback avoidance, which in turn positively led to help-seeking from co-workers. Moreover, the mediating effect of supervisory feedback avoidance was stronger at the high value of co-worker support than that at the low value of co-worker support. This study contributes to the recently emerged notion in abusive supervision research that supervisees’ perception of abusive supervision may not always lead to abundantly reported negative work behaviours; instead, it may also lead to positive work behaviours, such as help-seeking behaviour that is highly beneficial for both supervisees and the organization.
Herein, we report the detailed optoelectronic characteristics of low cost fabricated pristine and 1, 5, 10, and 15 wt% Mg-doped ZnO films on the FTO substrate (MZO/FTO) through the spin coating technique. High crystallinity and single phase of the film were confirmed by X-ray diffraction investigation. The average crystallite size was in the range of 46–78 nm. Homogeneous distribution of Mg doping in ZnO was approved by elemental mapping analysis. The fiber-like surface morphology was confirmed by the scanning electron microscopy analysis. Optical transparency was observed in the range of 40–80% for the fabricated films. The optical band gaps for direct and indirect transitions obtained from Tauc’s relation are in the range of 3.103–3.283 eV and 2.423–2.968 eV, respectively. It is also observed that the energy gap of MZO films decreases with an increase in Mg doping from 1 to 15%. The respective stable values of absorption and refractive indices are obtained in the range of ∼0.036–0.088 and ∼1.71–2.1. The linear and nonlinear optical susceptibilities as well as the nonlinear refractive index values were calculated. Additionally, Z-scan measurement was carried out at 532 nm wavelength. The nonlinear absorption coefficient and the imaginary part of third-order nonlinear susceptibility were estimated and corresponding values are obtained in the range of 0.35–123 (×10−5) cm/W and 0.084–29.7 (×10−8) e.s.u., respectively. Moreover, the optical limiting threshold values were obtained in the range of 2.57–6.34 kJ/cm2. The MZO/FTO films are showing strong optical limiting behavior compared to pristine. The output results suggest that MZO films are better contenders for optoelectronic applications.
A commercially pure titanium (CP-Ti) of grade 1 as a hard-to-deform material was processed successfully by ECAP processing up to four passes at room temperature via the core–sheath method using a die with an internal channel angle of 90°. The simulation and analytical calculations demonstrated that imposed back pressure on the core was increased at each pass due to strain hardening of sheath metal (AISI 1015 steel) during deformation which prevented damage accumulation and crack initiation at a high number of passes. The scanning electron microscopy and transmission electron microscopy observations of ECAP-processed Ti revealed a severely deformed microstructure which consisted of a high dislocation density and an average grain size of ∼250 nm. Mechanical properties of four-pass ECAP-processed CP-Ti showed a substantial enhancement of ultimate tensile strength up to 890 MPa associated with a reasonable elongation to failure of 15.3%.
Increasing evidence has suggested an association between food insecurity and the risk of anaemia. Therefore, a systematic review and meta-analysis were performed to examine the associations between food insecurity and anaemia risk.
Pertinent studies were identified by searching PubMed and EMBASE databases up to August 2017. Data were available from nineteen studies; seventeen studies were cross-sectional and two studies were longitudinal. Risk ratios of 95993 individual participants from twelve different countries in these studies were pooled for the meta-analysis.
The results showed that there was an overall positive relationship between food insecurity and anaemia risk (OR=1·27; 95 % CI 1·13, 1·40). Similar results were observed for Fe-deficiency anaemia (OR=1·45; 95 % CI 1·04, 1·86). These results revealed that food insecurity at two levels, including mild food insecurity (OR=1·15; 95 % CI 1·00, 1·31) and moderate food insecurity (OR=1·36; 95 % CI 1·23, 1·48), increased the risk of anaemia. In addition, it was found that age had an impact on the associations between food insecurity and anaemia risk (OR=1·22; 95 % CI 1·09, 1·36). Age subgroup analysis indicated that food insecurity significantly increased the risk of anaemia among infants/toddlers (OR=1·17; 95 % CI 1·05, 1·29) and adult women (OR=1·35; 95 % CI 1·16, 1·54).
It seems that infants, toddlers and adult women in food-insecure households are at a higher risk of anaemia. To prevent anaemia in food-insecure households, these age groups may require more nutritional support.
The effectiveness of Early Intervention in Psychosis (EIP) services for individuals with a first episode of psychosis (FEP) could be thwarted by high rates of early disengagement.
To investigate which factors predict disengagement with EIP services.
Using data from a naturalistic cohort of 786 EIP clients in East Anglia (UK), we investigated the association between sociodemographic and clinical predictors and disengagement using univariable and multivariable Cox proportional hazards models.
Over half (54.3%) of our sample were discharged before receiving 3 years of EIP care, with 92 (11.7%) participants discharged due to disengagement. Milder negative symptoms, more severe hallucinations, not receiving an FEP diagnosis, polysubstance use and being employed were associated with greater disengagement.
Our findings highlight heterogeneous reasons for disengagement with EIP services. For some patients, early disengagement may hinder efforts to sustain positive long-term EIP outcomes. Efforts to identify true FEP cases and target patients with substance use problems and more severe positive symptoms may increase engagement.
Background: Patients suffering from traumatic brain injury (TBI) are at increased risk of venous thromboembolism (VTE). However, initiation of pharmacological venous thromboprophylaxis (VTEp) may cause further intracranial hemorrhage. We reviewed the literature to determine the postinjury time interval at which VTEp can be administered without risk of TBI evolution and hematoma expansion. Methods: MEDLINE and EMBASE databases were searched. Inclusion criteria were studies investigating timing and safety of VTEp in TBI patients not previously on oral anticoagulation. Two investigators extracted data and graded the papers’ levels of evidence. Randomized controlled trials were assessed for bias according to the Cochrane Collaboration Tool and Cohort studies were evaluated for bias using the Newcastle-Ottawa Scale. We performed univariate meta-regression analysis in an attempt to identify a relationship between VTEp timing and hemorrhagic progression and assess study heterogeneity using an I2 statistic. Results: Twenty-one studies were included in the systematic review. Eighteen total studies demonstrated that VTEp postinjury in patients with stable head computed tomography scan does not lead to TBI progression. Fourteen studies demonstrated that VTEp administration 24 to 72 hours postinjury is safe in patients with stable injury. Four studies suggested that administering VTEp within 24 hours of injury in patients with stable TBI does not lead to progressive intracranial hemorrhage. Overall, meta-regression analysis demonstrated that there was no relationship between rate of hemorrhagic progression and VTEp timing. Conclusions: Literature suggests that administering VTEp 24 to 48 hours postinjury may be safe for patients with low-hemorrhagic-risk TBIs and stable injury on repeat imaging.