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 email@example.com
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.
To assess the relapse-free survival (RFS) and the factors influencing local recurrence in patients with desmoid fibromatosis (DF) treated at our centre and to determine the role of post-operative radiotherapy (RT) in improving local control.
A retrospective analysis of 51 patients treated for DF from January 2004 to December 2013 was undertaken. The RFS was calculated using the Kaplan–Meier curve. Univariate analysis was done to assess correlation with tumour size, site, the extent of surgery, margin status and adjuvant RT with RFS.
The median age was 28 years with a male:female ratio of 1:3. The most common location of the tumour was anterior abdominal wall (47%). The median tumour size was 10 cm. Wide local excision was done in most patients. Complete resection with negative margin was achieved in eight patients. Post-operative RT was indicated for 43 patients of whom 19 received RT. At a median follow-up of 37 months, RFS in the complete resection with margin negative group was 100%. RFS for the patients with positive or close margins who received RT was 79% and for those who did not receive RT, it was 87%.
Complete excision with negative margins gives the best local control in DF. The benefit of post-operative RT could not be ascertained.
Chemically modified polymer coatings have been synthesized using a blend of soft polymeric material polydimethylsiloxane (h-PDMS) incorporated with stiff polymer epoxy resin (EP) and was cross-linked using silane compatibilizer 3-aminopropyltriethoxysilane (APTES). A comparative analysis has been carried out between neat epoxy coating (N-EP) and epoxy–hydroxy-terminated polydimethylsiloxane (EP-hPD) blends to study the influence of blending ratio on various properties to cater marine applications. An increase of 144.4% in the Young’s modulus (E) and 37.5% increment in adhesion strength at 30 wt% h-PDMS content was observed as compared with N-EP. The water contact angle results demonstrated a substantial increase in contact angle from 52.3° to 90.1° at 30 wt% h-PDMS content as compared to N-EP. Taber abrasion results revealed a decrease in weight loss (mg/1000 cycles) by 24.1 and 17.7% at 10 and 30 wt% loading of h-PDMS in comparison to N-EP. The surface roughness of N-EP and 30 wt% EP-hPD blend were found to be 33.4 nm and 41.4 nm, respectively. To determine the applicability of the developed blend coatings obligatory tests such as field immersion study and chemical resistance evaluation were conducted, and optimum performance was manifested by EP-hPD blend at an EP:h-PDMS ratio of 70:30.
Vasodilation occurs as a result of the relaxation of the smooth muscle cells present in the walls of blood vessels. Various suitable models are available for the analysis of the vasoactive properties of drugs with therapeutic applications. But all these models have limitations, such as ethical issues and high cost. The purpose of this study is to develop an alternative model for studying the vasoactive properties of drugs using an in-ovo chicken embryo model. In the preliminary experiment, we used a well-known vasoconstrictor (adrenaline) and a vasodilator (spermine NoNoate) in the chick embryo area vasculosa and evaluated their concentration-response curve. Adrenaline (10 µM) and spermine NoNoate (10 µM) were administered in different arteries and veins and different positions of the right vitelline artery of the chick embryo. Results showed the middle of the vessel bed of the right vitelline artery having the best vasoactive effect compared to others. Finally, anti-hypertensive drugs, calcium channel blockers, and NOS agonists were administered in the chick embryo area vasculosa to validate the model. Results demonstrate that the chick embryo area vasculosa can be an alternative, robust, and unique in-ovo model for screening of anti-hypertensive drugs in real time.
High-intensity electron linacs have severe space-charge effects that lead to the production of beam halo which degrade the beam quality. For a given charge per bunch, hollow beams have a weaker nonlinear space-charge force. In this paper, we have investigated the possibility of using hollow beam to control halo growth in linacs. We simulate the dynamics of such a beam in a 17 MeV radio frequency linac using ASTRA beam dynamics code and show that it experiences a smaller emittance growth as well as reduced beam halo. The results suggest that using a hollow beam, high charge per bunch could be propagated and accelerated in a radio frequency linac.
This paper deals with the kinematic analysis and enumeration of singularities of the six degree-of-freedom 3-RPS-3-SPR series–parallel manipulator (S–PM). The characteristic tetrahedron of the S–PM is established, whose degeneracy is bijectively mapped to the serial singularities of the S–PM. Study parametrization is used to determine six independent parameters that characterize the S–PM and the direct kinematics problem is solved by mapping the transformation matrix between the base and the end-effector to a point in ℙ7. The inverse kinematics problem of the 3-RPS-3-SPR S–PM amounts to find the location of three points on three lines. This problem leads to a minimal octic univariate polynomial with four quadratic factors.
Dermatofibrosarcoma protuberans (DFSP) is a locally aggressive intermediate malignancy.
The purpose of this retrospective analysis is to determine the efficacy of radiation therapy (RT) in local control of DFSP.
Patients and methods
The recurrence-free survival (RFS) for 45 patients treated for DFSP at our institution was estimated and compared between surgery alone and postoperative RT groups.
Age range of the patients were in the third and fourth decades; males:females=2:1; most common site: anterior abdominal wall; tumours >5 cm in size in 75%; low grade in 77·8%; margins positive in 31·8% and <5 mm margins in 45·5%. Two-thirds of patients had at least one recurrence before presentation to our institution. RT dose was >50 Gy in 88% of patients. The patients treated with postoperative RT had poorer prognostic factors compared with surgery alone: they were males (17 versus 13 patients), and presented with high-grade tumours (5 versus 1 patients), multiple recurrences prior to presentation (25 versus 20 patients) and positive or <5 mm margins (22 versus 12 patients). Median follow-up for surgery alone group was 17 (1–152) months and for postoperative RT group, this was 54 (5–121) months. RFS at 5 years was 77·1% for surgery alone and 87·9% for postoperative RT group but was not statistically significant. The median time to recurrence was 4 years.
RT delays the time to recurrence in DFSP. RT improves the outcome of DFSP for recurrent tumours and with positive margins.
ICAR-Directorate of Cashew Research is the nodal agency for conducting cashew research and manages the largest field gene bank in India. Cashew is a perennial tree and needs more land and other resources to maintain accessions. Conservation through seeds is not feasible because of cross-pollination. Tissue culture efforts to regenerate plants from mature explants are not successful. Therefore, efficient management of the filed gene bank particularly utilization requires designation of the core collection representing the spectrum of diversity present in the entire collection. In this study, a relatively new technique, the advanced M strategy with heuristic approach was deployed to develop the core collection. Sixty-eight morphometric characters of 478 accessions were subjected to analysis resulting in the core collection of 49 accessions. Further, another core collection of same number was constituted by K-Means clustering to compare the efficiency of two approaches. The validation parameters like mean difference, variance difference, coincidence rate, variable rate and class coverage among others were employed for comparative analysis. The results of these parameters revealed that the core collection designated by heuristic approach was better able to efficiently represent and retain the diversity of the entire collection compared with the core identified by clustering approach. Future conservation and breeding efforts will be focused on establishing a separate block in the field gene bank having 49 accessions of cashew core collection.
The solar active region (AR) 12192 was one of the most flare productive region of solar cycle 24, which produced many X-class flares; the most energetic being an X3.1 flare on October 24, 2014 at 21:10 UT. Customarily, such events are believed to be triggered by magnetic reconnection in coronal magnetic fields. Here we use the vector magnetograms from solar photosphere, obtained from Heliospheric Magnetic Imager (HMI) to investigate the magnetic field topology prior to the X3.1 event, and ascertain the conditions that might have caused the flare. To infer the coronal magnetic field, a novel non-force-free field (NFFF) extrapolation technique of the photospheric field is used, which suitably mimics the Lorentz forces present in the photospheric plasma. We also highlight the presence of magnetic null points and quasi-separatrix layers (QSLs) in the magnetic field topology, which are preferred sites for magnetic reconnections and discuss the probable reconnection scenarios.
Magnetic reconnections (MRs) for various magnetic field line (MFL) topologies are believed to be the initiators of solar eruptive events like flares and coronal mass ejections (CMEs). Consequently, important is a thorough understanding and quantification of the MFL topology and their evolution which leads to MRs. Contemporary standard is to extrapolate the coronal MFLs using equilibrium models where the Lorentz force on the coronal plasma is zero everywhere. In tandem, a non-force-free-field (NFFF) extrapolation scheme has evolved and allows for a Lorentz force which is non-zero only at the photosphere but asymptotically vanishes with height. The paper reports magnetohydrodynamic (MHD)- simulations initiated by NFFF extrapolation of the coronal MFLs for a flare producing active region NOAA 11158. Interestingly, quasi-separatrix layers (QSLs) which facilitate MRs are detected in the extrapolated MFLs and, here the paper makes an attempt to asses the role of QSLs in the flare onsets.