Cochlea-sparing acoustic neuroma treatment with 4π radiation therapy.

PurposeThis study investigates whether 4π noncoplanar radiation therapy can spare the cochleae and consequently potentially improve hearing preservation in patients with acoustic neuroma who are treated with radiation therapy.Methods and materialsClinical radiation therapy plans for 30 patients with acoustic neuroma were included (14 stereotactic radiation surgery [SRS], 6 stereotactic radiation therapy [SRT], and 10 intensity modulated radiation therapy [IMRT]). The 4π plans were created for each patient with 20 optimal beams selected using a greedy column generation method and subsequently recalculated in Eclipse for comparison. Organ-at-risk (OAR) doses, homogeneity index, conformity, and tumor control probability (TCP) were compared. Normal tissue complication probability (NTCP) was calculated for sensorineural hearing loss (SNHL) at 3 and 5 years posttreatment. The dose for each plan was then escalated to achieve 99.5% TCP.Results4π significantly reduced the mean dose to both cochleae by 2.0 Gy (32%) for SRS, 3.2 Gy (29%) for SRT, and 10.0 Gy (32%) for IMRT. The maximum dose to both cochleae was also reduced with 4π by 1.6 Gy (20%), 2.2 Gy (15%), and 7.1 Gy (18%) for SRS, SRT, and IMRT plans, respectively. The reductions in mean/maximum brainstem dose with 4π were also statistically significant. Mean doses to other OARs were reduced by 19% to 56% on average. 4π plans had a similar CN and TCP, with a significantly higher average homogeneity index (0.93 vs 0.92) and significantly lower average NTCP for SNHL at both 3 years (30.8% vs 40.8%) and 5 years (43.3% vs 61.7%). An average dose escalation of approximately 116% of the prescription dose achieved 99.5% TCP, which resulted in 32.6% and 43.4% NTCP for SNHL at 3 years and 46.4% and 64.7% at 5 years for 4π and clinical plans, respectively.ConclusionsCompared with clinical planning methods, optimized 4π radiation therapy enables statistically significant sparing of the cochleae in acoustic neuroma treatment as well as lowering of other OAR doses, potentially reducing the risk of hearing loss

The angiotensin-converting enzyme (ACE) gene family of Anopheles gambiae

Background Members of the M2 family of peptidases, related to mammalian angiotensin converting enzyme (ACE), play important roles in regulating a number of physiological processes. As more invertebrate genomes are sequenced, there is increasing evidence of a variety of M2 peptidase genes, even within a single species. The function of these ACE-like proteins is largely unknown. Sequencing of the A. gambiae genome has revealed a number of ACE-like genes but probable errors in the Ensembl annotation have left the number of ACE-like genes, and their structure, unclear. Results TBLASTN and sequence analysis of cDNAs revealed that the A. gambiae genome contains nine genes (AnoACE genes) which code for proteins with similarity to mammalian ACE. Eight of these genes code for putative single domain enzymes similar to other insect ACEs described so far. AnoACE9, however, has several features in common with mammalian somatic ACE such as a two domain structure and a hydrophobic C terminus. Four of the AnoACE genes (2, 3, 7 and 9) were shown to be expressed at a variety of developmental stages. Expression of AnoACE3, AnoACE7 and AnoACE9 is induced by a blood meal, with AnoACE7 showing the largest (approximately 10-fold) induction. Conclusion Genes coding for two-domain ACEs have arisen several times during the course of evolution suggesting a common selective advantage to having an ACE with two active-sites in tandem in a single protein. AnoACE7 belongs to a sub-group of insect ACEs which are likely to be membrane-bound and which have an unusual, conserved gene structure

A Novel Design and Implementation of Dos-Resistant Authentication and Seamless Handoff Scheme for Enterprise WLANs

With the advance of wireless access technologies, the IEEE 802.11 wireless local area network (WLAN) has gained significant increase in popularity and deployment due to the substantially improved transmission rate and decreased deployment costs. However, this same widespread deployment makes WLANs an attractive target for network attacks. Several vulnerabilities have been identified and reported regarding the security of the current 802.11 standards. To address those security weaknesses, IEEE standard committees proposed the 802.11i amendment to enhance WLAN security. The 802.11i standard has demonstrated the capability of providing satisfactory mutual authentication, better data confidentiality, and key management support, however, the design of 802.11i does not consider network availability. Thus 802.11i is highly susceptible to malicious denial-of-service (DoS) attacks, which exploit the vulnerability of unprotected management frames. This paper proposes, tests and evaluates a combination of three novel methods by which the exploitation of 802.11i by DoS attacks can be improved. These three methods include an access point nonce dialogue scheme, a fast access point transition protocol handoff scheme and a location management based selective scanning scheme. This combination is of particular value to real-time users running time-dependant applications such as VoIP. In order to acquire practical data to evaluate the proposed schemes, a prototype network has been implemented as an experimental testbed using open source tools and drivers. This testbed allows practical data to be collected and analysed. The result demonstrates that not only the proposed authentication scheme eradicates most of the DoS vulnerabilities, but also substantially improved the handoff performance to a level suitable for supporting real-time services

Impact of Human Immunodeficiency Virus in the Pathogenesis and Outcome of Patients with Glioblastoma Multiforme.

BackgroundImprovement in antiviral therapies have been accompanied by an increased frequency of non-Acquired Immune Deficiency Syndrome (AIDS) defining malignancies, such as glioblastoma multiforme. Here, we investigated all reported cases of human immunodeficiency virus (HIV)-positive patients with glioblastoma and evaluated their clinical outcomes. A comprehensive review of the molecular pathogenetic mechanisms underlying glioblastoma development in the setting of HIV/AIDS is provided.MethodsWe performed a PubMed search using keywords "HIV glioma" AND "glioblastoma," and "AIDS glioma" AND "glioblastoma." Case reports and series describing HIV-positive patients with glioblastoma (histologically-proven World Health Organization grade IV astrocytoma) and reporting on HAART treatment status, clinical follow-up, and overall survival (OS), were included for the purposes of quantitative synthesis. Patients without clinical follow-up data or OS were excluded. Remaining articles were assessed for data extraction eligibility.ResultsA total of 17 patients met our inclusion criteria. Of these patients, 14 (82.4%) were male and 3 (17.6%) were female, with a mean age of 39.5±9.2 years (range 19-60 years). Average CD4 count at diagnosis of glioblastoma was 358.9±193.4 cells/mm3. Tumor progression rather than AIDS-associated complications dictated patient survival. There was a trend towards increased median survival with HAART treatment (12.0 vs 7.5 months, p=0.10).ConclusionOur data suggests that HAART is associated with improved survival in patients with HIV-associated glioblastoma, although the precise mechanisms underlying this improvement remain unclear

Magnetotransport in a bi-crystal film of La_0.7Sr_0.3MnO_3

Transport properties of an epitaxial film of La_0.7Sr_0.3MnO_3 (LSMO), deposited epitaxially on a LaAlO_3 bi-crystal substrate having a misorientation angle of 9.2 deg., have been studied. The film was patterned into a meander containing 100 grain boundaries. The resistivity of the sample exhibits two components; one originating from the grain boundary regions, and one from the LSMO elements in the meander; the latter contribution is similar to the resistivity of a reference epitaxial LSMO film. The low (<0.5 T) and high (up to 6 T) field magnetoresistance was also studied. The meander show a large low field magnetoresistance, increasing with decreasing temperature, and a constant high field slope of the magnetoconductance, results that are well explained by a two-step spin polarized tunneling model.Comment: ICM2000 contribution - 6 pages, 3 figure

Reconstruction of extended regions in EIT with a generalized Robin transmission condition

We consider an inverse shape problem coming from electrical impedance tomography with a generalized Robin transmission condition. We will derive an algorithm in order to detect whether two materials that should be in contact are separated or delaminated. More precisely, we assume that the undamaged material or background state is known and shares an interface or boundary with the damaged subregion. The Robin transmission condition on this boundary asymptotically models delamination. We assume that the DtN operator is given from measuring the current on the surface of the material from an imposed voltage. We show that this mapping uniquely recovers the boundary parameters. Furthermore, using this electrostatic Cauchy data as physical measurements, we can determine if all of the coefficients from the Robin transmission condition are real-valued or complex-valued. We study these two cases separately and show that the regularized factorization method can be used to detect whether delamination has occurred and recover the damaged subregion. Numerical examples will be presented for both cases in two dimensions in the unit circle.Comment: arXiv admin note: substantial text overlap with arXiv:2203.0955

Improved Pill Splitter: An Analysis of 3&4-Point Bending to Split Pills

There is a niche in the pill splitting industry for a more efficient pill splitter. To fill this niche we explore various applications of 3-Point and 4-Point bending to pill splitting. All designs are 3D printed. Due to the elastic nature of PLA plastic, the reality that 3-Point bending may cause pills to fail in compression (as revealed by FEM analysis), and the difficulty in managing volume constraints in a 3-Point bending design, 4-Point bending is considered as a viable option for pill splitting. However, after testing and analysis, the 4-Point bending prototypes generated were able to break pills, but not split in half, which is unacceptable