8,539 research outputs found
When chiral photons meet chiral fermions - Photoinduced anomalous Hall effects in Weyl semimetals
The Weyl semimetal is characterized by three-dimensional linear band touching
points called Weyl nodes. These nodes come in pairs with opposite chiralities.
We show that the coupling of circularly polarized photons with these chiral
electrons generates a Hall conductivity without any applied magnetic field in
the plane orthogonal to the light propagation. This phenomenon comes about
because with all three Pauli matrices exhausted to form the three-dimensional
linear dispersion, the Weyl nodes cannot be gapped. Rather, the net influence
of chiral photons is to shift the positions of the Weyl nodes. Interestingly,
the momentum shift is tightly correlated with the chirality of the node to
produce a net anomalous Hall signal. Application of our proposal to the
recently discovered TaAs family of Weyl semimetals leads to an
order-of-magnitude estimate of the photoinduced Hall conductivity which is
within the experimentally accessible range.Comment: 9 pages, 4 figure
Sargassum fulvellum
Ultraviolet (UV) radiation has been reported to induce cutaneous inflammation such as erythema and edema via induction of proinflammatory enzymes and mediators. Sargassum fulvellum is a brown alga of Sargassaceae family which has been demonstrated to exhibit antipyretic, analgesic, antiedema, antioxidant, antitumor, fibrinolytic, and hepatoprotective activities. The purpose of this study is to investigate anti-inflammatory effects of ethylacetate fraction of ethanol extract of Sargassum fulvellum (SFE-EtOAc) in HaCaT keratinocytes and BALB/c mice. In HaCaT cells, SFE-EtOAc effectively inhibited UVB-induced cytotoxicity (60 mJ/cm2) and the expression of proinflammatory proteins such as cyclooxygenase-2 (COX-2), tumor necrosis factor-α (TNF-α), and inducible nitric oxide synthase (iNOS). Furthermore, SFE-EtOAc significantly reduced UVB-induced production of proinflammatory mediators including prostaglandin E2 (PGE2) and nitric oxide (NO). In BALB/c mice, topical application of SFE-EtOAc prior to UVB irradiation (200 mJ/cm2) effectively suppressed the UVB-induced protein expression of COX-2, iNOS, and TNF-α and subsequently attenuated generation of PGE2 and NO as well. In another experiment, SFE-EtOAc pretreatment suppressed UVB-induced reactive oxygen species production and exhibited an antioxidant potential by upregulation of antioxidant enzymes such as catalase and Cu/Zn-superoxide dismutase in HaCaT cells. These results suggest that SFE-EtOAc could be an effective anti-inflammatory agent protecting against UVB irradiation-induced skin damages
Simultaneous deletion of floxed genes mediated by CaMKIIa-Cre in the brain and in male germ cells: application to conditional and conventional disruption of Go-alfa
The Cre/LoxP system is a well-established approach to spatially and temporally control genetic inactivation. The calcium/calmodulin-dependent protein kinase II alpha subunit (CaMKIIα) promoter limits expression to specific regions of the forebrain and thus has been utilized for the brain-specific inactivation of the genes. Here, we show that CaMKIIα-Cre can be utilized for simultaneous inactivation of genes in the adult brain and in male germ cells. Double transgenic Rosa26+/stop-lacZ::CaMKIIα-Cre+/Cre mice generated by crossing CaMKIIα-Cre+/Cre mice with floxed ROSA26 lacZ reporter (Rosa26+/stop-lacZ) mice exhibited lacZ expression in the brain and testis. When these mice were mated to wild-type females, about 27% of the offspring were whole body blue by X-gal staining without inheriting the Cre transgene. These results indicate that recombination can occur in the germ cells of male Rosa26+/stop-lacZ::CaMKIIα-Cre+/Cre mice. Similarly, when double transgenic Gnao+/f::CaMKIIα-Cre+/Cre mice carrying a floxed Go-alpha gene (Gnaof/f) were backcrossed to wild-type females, approximately 22% of the offspring carried the disrupted allele (GnaoΔ) without inheriting the Cre transgene. The GnaoΔ/Δ mice closely resembled conventional Go-alpha knockout mice (Gnao−/−) with respect to impairment of their behavior. Thus, we conclude that CaMKIIα-Cre mice afford recombination for both tissue- and time-controlled inactivation of floxed target genes in the brain and for their permanent disruption. This work also emphasizes that extra caution should be exercised in utilizing CaMKIIα-Cre mice as breeding pairs.Fil: Choi, Chan-Il. Ajou University. School of Medicine; Corea del SurFil: Yoon, Sang-Phil. Ajou University. School of Medicine; Corea del SurFil: Choi, Jung-Mi. Ajou University. School of Medicine; Corea del SurFil: Kim, Sung-Soo. Ajou University. School of Medicine; Corea del SurFil: Lee, Young-Don. Ajou University. School of Medicine; Corea del SurFil: Birnbaumer, Lutz. National Institute of Environmental Health Sciences; Estados Unidos. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires". Instituto de Investigaciones Biomédicas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; ArgentinaFil: Suh-Kim. Haeyoung. Ajou University. School of Medicine; Corea del Su
Allele Frequency and Genotype Distribution of STR SE33 locus in Koreans
DNA was obtained from placental tissue and peripheral blood of
268 unrelated Koreans in order to analyze the applicability of PCR amplification
of human beta-actin related pseudogene H-beta-Ac-psi-2 (AClBP-2, SE33) SlR locus
for forensic medicine in the field of individual identification and paternity tests.
After amplification using two primers specific to the SE33 locus, the products
were analyzed by polyacrylmide gel electrophoresis, so called Amp-FLP(Amplification
Fragment Length Polymorphism) procedure followed by silver staining. To
improw the differentiation of the allele an automatic sequencer, Licor 4000-L was
used and the result was compared with that of routine acrylamide gel electrophoresis.
36 alleles were deteced, and the distribution was somewhat homogenous, and
none of the alleles were above 0.1 in frequency. Allele 12 and allele 14 were most
frequent with frequencies of 0.09701 and 0.08022, and alleles of two base repeat
such as allele 17, allele 19 were also encountered. 144 kinds of genotypes were
found, among which 22 were homozygotes, and the heterozygosity was 91.85%. In
164 gametes of 64 families whose parent-child relationship were confirmed through
other studies and information, Mendelian inheritance was well presented although
two mutations were observed
Intraocular Involvement of a Nasal Natural Killer T-Cell Lymphoma: A Case Report
Herein, we report a case of nasal natural killer T-cell lymphoma (NKTL) with intraocular involvement. A 57-year-old woman was referred due to a three-day history of photophobia and diplopia in the left eye. One-month previously, she was diagnosed with nasal NKTL of the right nasal cavity. Ophthalmic examination revealed conjunctival injection and ptosis. The left pupil was fully dilated and non-reactive to light. Ocular motion was restricted on left-upper gaze. Five days later, anterior uveitis developed and persisted despite topical steroid treatment. An orbital magnetic resonance imaging was without specific findings, however, ophthalmoplegia, vitreous opacity, and an iris mass were observed. A diagnostic anterior chamber aspiration was performed. Aqueous humor aspiration revealed 35% morphologically atypical lymphocytes. After an intravitreal triamcinolone injection, radiotherapy and chemotherapy were administered; this resolved the uveitis and iris mass. When refractory uveitis or orbital pseudotumor occurs in patients with nasal NKTL, ocular and orbital involvement of the NKTL should be considered
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