Heterostructured TiO2/C/Co nanomaterial has been derived from a carbonized zeolitic imidazolate (ZIF-67) porous framework. The obtained uniform nanospheres wrapped with TiO2 have shown superior microwave absorption properties. Traditionally, the interaction of phonons within a confined system in terms of microwave absorption has not been studied in the literature to date. Here, we demonstrate that the phonon confinement is pivotal in the improvement of impedance matching, besides the multiple interfacial dielectric relaxations at different dielectric media (TiO2/C, C/Co) in the composite. Because of the specially crafted phonon confinement and multiple interface dielectric relaxations, the as-synthesized (TiO2/C/Co) composite manifests a maximum reflection loss of −42 dB with a broad bandwidth of 5 GHz. This work explains the possible mechanism of electromagnetic shielding in a confined system with multiple interfaces and may lead to design of advanced materials for microwave shielding.

BackgroundHybrid peripheral nerve sheath tumors (PNSTs) have been recognized recently and were first included in the 4th edition of World Health Organization (WHO) Classification of Tumors of Soft tissue and Bone, published in 2013. These tumors show combined features of more than one type of conventional benign peripheral nerve sheath tumors. The most common combinations are those of schwannoma/perineurioma followed by combinations of neurofibroma/schwannoma and neurofibroma/perineurioma. A detailed literature review of published cases is presented.We have discussed the types and etiology, epidemiology and sites of localization, gross and microscopic appearances and immunohistochemical features of hybrid PNSTs and association of these tumors with tumor syndromes.Case presentationWe have included five cases which were diagnosed in our department as we believe that publication of these new cases is relevant for the improved understanding of these specific tumors. Four of our five patients were males, mean age was 24 years. There was wide variation in the location of these tumors. Mean size of excised tumors was 5.5 cms in the greatest dimensions. Three out of five cases represented hybrid schwannoma/perineurioma histologically. No significant nuclear atypia, mitotic activity or necrosis seen. All five cases were completely excised. All five patients are alive and well at the time of writing with no recurrence.ConclusionHybrid PNSTs are distinct tumors and are usually benign. However, rare case reports have described local recurrence and at least two recent case reports have described malignant transformation in these tumors. Further studies on large number of cases are required to determine the exact pathogenetic basis of these tumors.

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IntroductionMucinous cystadenoma is a type of mucocele of the appendix that is rarely encountered in clinical practice. Dogmatic consensus on the optimal surgical modus operandi of appendicular mucocele is lacking in the literature and this remains a subject of controversy. There is little agreement with regard to the best procedure (right hemicolectomy versus appendectomy) or the best surgical approach (laparoscopic versus laparotomy).Case presentationWe report the case of a 70-year-old Asian woman from Karachi who presented with pain in the right iliac fossa for 15 days. On physical examination, a mobile and firm mass was palpable in the right iliac fossa. A colonoscopy was performed which showed external compression of the cecum. A biopsy of the mucosa was normal. Computed tomography scan showed a mucocele of the appendix with minimal periappendiceal fat stranding. She underwent an initial diagnostic laparoscopy to evaluate any mucin spillage in the peritoneal cavity. Once no spillage was identified, an open appendectomy was then performed. Intra-operatively, a frozen section of the appendiceal sample was sent to ascertain the need for an extension of surgery to a right hemicolectomy. Absence of any malignancy on the frozen section obviated the need for a surgical extension. The final histopathological examination showed a mucinous cystadenoma of the appendix. The patient was symptom-free at one year after surgery.ConclusionIt is important to distinguish between mucinous cystadenomas and mucinous cystadenocarcinomas. However, this distinction remains elusive in the pre-operative setting. A simple appendectomy using an intra-operative frozen section appears to be a reasonable surgical approach for selected cases with an intact mucocele of the appendix. However, long-term follow-up is warranted in such patients to evaluate the risks of using this approach.

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BackgroundHelicobacter pylori (H. pylori) infection is known to be associated with a spectrum of gastroduodenal diseases. We studied the association of H. pylori virulence markers cytotoxin-associated gene (cagA) and vacuolating associated cytotoxin gene (vacA) alleles in patients with non ulcer dyspepsia (NUD), gastric ulcer (GU), gastric carcinoma (GC) and duodenal ulcer (DU).MethodsH. pylori infection established by both rapid urease test and histology were studied. The cagA and vacA allelic status was determined by polymerase chain reaction (PCR). Sequencing of vacA i1 and i2 PCR product was carried out.ResultsTwo hundred and twenty-four patients were included, 141 (63%) were males with a mean age of 45 ± 16, range 16-83 years. The virulence marker cagA was associated with GU in 20(63%) (p = 0.04), DU in 23(72%) (p = 0.003) and GC in 29(73%) (p = 0.001) compared to NUD in 51(42%). VacA s1am1 was associated with GU in 23(72%) (p = 0.001), DU in 17(53%) (p < 0.001) and GC in 23(58%) (p = 0.003) compared to NUD in 38(32%) while vacA s1bm1 was also associated with GU in 9(28%) (p = 0.001), DU in 12(37%) (p < 0.001) and GC 11(28%) (p < 0.001) compared to NUD in 13(11%), respectively. The diagnoses of GU in 21(66%), DU in 16(50%), GC in 20(50%) and NUD in 50(42%) were associated with moderately active chronic inflammation. CagA in 55(45%) (p = 0.037), vacA s1am1 in 51(51%) (P < 0.001), s1bm1 in 25(56%) (p = 0.002), s1am2 32(30%) (p < 0.001) and s1bm2 29(69%) (p = 0.004) were also associated with moderately active chronic inflammation.ConclusionCagA was negative in majority of NUD patients with H. pylori infection. However, cagA was associated with peptic ulcer and GC. VacA allele's s1am1 and s1bm1 were associated with H. pylori associated diseases and inflammation.

The switch from an outcrossing mode of mating enforced by self-incompatibility to self-fertility in the Arabidopsis thaliana lineage was associated with mutations that inactivated one or both of the two genes that comprise the self-incompatibility (SI) specificity-determining S-locus haplotype, the S-locus receptor kinase (SRK) and the S-locus cysteine-rich (SCR) genes, as well as unlinked modifier loci required for SI. All analyzed A. thaliana S-locus haplotypes belong to the SA, SB, or SC haplotypic groups. Of these three, the SC haplotype is the least well characterized. Its SRKC gene can encode a complete open-reading frame, although no functional data are available, while its SCRC sequences have not been isolated. As a result, it is not known what mutations were associated with inactivation of this haplotype. Here, we report on our analysis of the Lz-0 accession and the characterization of its highly rearranged SC haplotype. We describe the isolation of its SCRC gene as well as the subsequent isolation of SCRC sequences from other SC-containing accessions and from the A. lyrata S36 haplotype, which is the functional equivalent of the A. thaliana SC haplotype. By performing transformation experiments using chimeric SRK and SCR genes constructed with SC-and S36-derived sequences, we show that the SRKC and SCRC genes of Lz-0 and at least a few other SC-containing accessions are nonfunctional, despite SCRC encoding a functional full-length protein. We identify the probable mutations that caused the inactivation of these genes and discuss our results in the context of mechanisms of S-locus inactivation in A. thaliana.T HE switch from an outcrossing mode of mating to selffertility was a major transition in the evolutionary history of Arabidopsis thaliana. Recent studies have shown that this switch was accompanied by multiple independent losses of self-incompatibility (SI), the major mechanism that promotes outcrossing in the Brassicaceae Shimizu et al. 2008; Boggs et al. 2009a). In this family, SI is controlled by numerous haplotypes of the S locus. Within each S-locus haplotype (hereafter S haplotype), are two genes that determine specificity in the SI response: one gene encodes the stigma-expressed S-locus receptor kinase (SRK) and the other encodes the pollen coat-localized ligand for SRK, the S-locus cysteine-rich (SCR) protein. The SRK and SCR proteins are highly polymorphic and co-evolving proteins (Sato et al. 2002) and their haplotype-specific interaction is responsible for the specific recognition and inhibition by the stigma epidermis of self-related pollen (i.e., pollen derived from the same flower, other flowers on the same plant, or plants expressing the same S haplotype) (reviewed in Rea and Nasrallah 2008). Consequently, an understanding of the genetic events associated with the switch to self-fertility in the A. thaliana lineage was sought through analysis of SRK and SCR sequences harbored by various A. thaliana geographical accessions (Kusaba et al. 2001;Shimizu et al. 2004Shimizu et al....

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