752 research outputs found
Sulfur isotope rations of sulfide minerals from the deposit of the Tsuchikura mine, Shiga Prafecture, Japan
Sulfur isotope rations of sulfide minerals in the ore specimens from the deposit of the Tsuchikura mine are distrib-uted in a range from -0.8 to 5.4%, mostly from +0.5 to 3.0%, close to the previous data (from +1 to +3%) by Miyake and Sasaki (1980). The distribution range is also similar to the major Besshi-type deposites of the Sambagawa terrain. Sulfur isotope fractionation between coexisting pyrite and chalcopyrite is not uniform. This may be largely due to spatial tearrangament of the initial orebodies to the present form. Sulfide minerals mostly pyrite from host rocks (siltsones, sandstones, basaltic rocks) exhibit remarkably low δ34S values ranging from -49.3 to -2.6%, dis-tinctly different from the δ34S values for sulfide minerals of ores. The low δ34S values may indicate the bacteriogenic origin of host rock sulfides, although it seems peculiar that basaltic rocks also have extremely low δ34S values
A trapped surface in the higher-dimensional self-similar Vaidya spacetime
We investigate a trapped surface and naked singularity in a -dimensional
Vaidya spacetime with a self-similar mass function. A trapped surface is
defined as a closed spacelike -surface which has negative both null
expansions. There is no trapped surface in the Minkowski spacetime. However, in
a four-dimensional self-similar Vaidya spacetime, Bengtsson and Senovilla
considered non-spherical trapped surfaces and showed that a trapped surface can
penetrate into a flat region, if and only if the mass function rises fast
enough [I. Bengtsson and J. M. M. Senovilla, Phys. Rev. D \textbf{79}, 024027
(2009).]. We apply this result to a -dimensional spacetime motivated by the
context of large extra dimensions or TeV-scale gravity. In this paper,
similarly to Bengtsson and Senovilla's study, we match four types of
-surfaces and show that a trapped surface extended into the flat region
can be constructed in the -dimensional Vaidya spacetime, if the increasing
rate of the mass function is greater than 0.4628. Moreover, we show that the
maximum radius of the trapped surface constructed here approaches the
Schwarzschild-Tangherlini radius in the large limit. Also, we show that
there is no naked singularity, if the spacetime has the trapped surface
constructed here.Comment: 13 pages, 5 figure
Pathogenesis and treatment of multiple myeloma bone disease
Multiple myeloma (Plasma cell myeloma), a malignancy of the plasma cells, exhibits tumor expansion preferentially in the bone marrow and the development of bone-destructive lesions. Multiple myeloma is still an incurable disease with changes in the bone marrow microenvironment in favor of the survival and proliferation of multiple myeloma cells and bone destruction. In this review, we described the recent findings on the regulators involved in the development of myeloma bone diseases, and succinctly summarize currently available therapeutic options and the development of novel bone modifying agents for myeloma treatment
Myeloma–Bone Interaction : A Vicious Cycle via TAK1–PIM2 Signaling
Myeloma cells interact with their ambient cells in the bone, such as bone marrow stromal cells, osteoclasts, and osteocytes, resulting in enhancement of osteoclastogenesis and inhibition of osteoblastogenesis while enhancing their growth and drug resistance. The activation of the TAK1–PIM2 signaling axis appears to be vital for this mutual interaction, posing it as an important therapeutic target to suppress tumor expansion and ameliorate bone destruction in multiple myeloma.Multiple myeloma (MM) has a propensity to develop preferentially in bone and form bone-destructive lesions. MM cells enhance osteoclastogenesis and bone resorption through activation of the RANKL–NF-κB signaling pathway while suppressing bone formation by inhibiting osteoblastogenesis from bone marrow stromal cells (BMSCs) by factors elaborated in the bone marrow and bone in MM, including the soluble Wnt inhibitors DKK-1 and sclerostin, activin A, and TGF-β, resulting in systemic bone destruction with loss of bone. Osteocytes have been drawn attention as multifunctional regulators in bone metabolism. MM cells induce apoptosis in osteocytes to trigger the production of factors, including RANKL, sclerostin, and DKK-1, to further exacerbate bone destruction. Bone lesions developed in MM, in turn, provide microenvironments suited for MM cell growth/survival, including niches to foster MM cells and their precursors. Thus, MM cells alter the microenvironments through bone destruction in the bone where they reside, which in turn potentiates tumor growth and survival, thereby generating a vicious loop between tumor progression and bone destruction. The serine/threonine kinases PIM2 and TAK1, an upstream mediator of PIM2, are overexpressed in bone marrow stromal cells and osteoclasts as well in MM cells in bone lesions. Upregulation of the TAK1–PIM2 pathway plays a critical role in tumor expansion and bone destruction, posing the TAK1–PIM2 pathway as a pivotal therapeutic target in MM
Microenvironment and radiation therapy
Dependency on tumor oxygenation is one of the major features of radiation therapy and this has led many radiation biologists and oncologists to focus on tumor hypoxia. The first approach to overcome tumor hypoxia was to improve tumor oxygenation by increasing oxygen delivery and a subsequent approach was the use of radiosensitizers in combination with radiation therapy. Clinical use of some of these approaches was promising, but they are not widely used due to several limitations. Hypoxia-inducible factor 1 (HIF-1) is a transcription factor that is activated by hypoxia and induces the expression of various genes related to the adaptation of cellular metabolism to hypoxia, invasion and metastasis of cancer cells and angiogenesis, and so forth. HIF-1 is a potent target to enhance the therapeutic effects of radiation therapy. Another approach is antiangiogenic therapy. The combination with radiation therapy is promising, but several factors including surrogate markers, timing and duration, and so forth have to be optimized before introducing it into clinics. In this review, we examined how the tumor microenvironment influences the effects of radiation and how we can enhance the antitumor effects of radiation therapy by modifying the tumor microenvironment
Massive Intravascular Hemolysis in a Patient Infected by a Clostridium perfringens
Clostridium perfringens infection is a very rare cause of massive intravascular hemolysis, but it
should always be kept in mind, since only early treatment can rescue patients from an otherwise rapidly
fatal outcome. We report a case of a 78-year-old diabetic male who was admitted complaining of
general fatigue, dark red urine, and vomiting. His blood revealed massive hemolysis. Computer
tomography demonstrated huge liver abscess in the right lobe of the liver. About 1 h after admission,
he suddenly fell into a critical condition. He died 3 h after admission in spite of intensive care and
resuscitation. Clostridium perfringens was detected from the blood taken before death and from
liver abscess by biopsy after death. We concluded that this patient died of acute massive intravascular
hemolysis in septicemia caused by Clostridium perfringens infection
Die politischen Kneipen in Berlin am Anfang der 1930er Jahren
Das Ziel dieser Abhandlung ist es, die Sachlage der politischen Kneipen in Berlin am Anfang der 1930er Jahren aufzuklären, die als der Ausgangspunkt der politischen Gewalt funktionierten. Dabei lege ich den Schwerpunkt besonders auf den inneren Zustand und die verschiedenen Funktionen der politischen Kneipen, das Verhalten ihrer Schankwirte, die Beziehungen zwischen den politischen Kneipen und ihren Umgebungen und das polizeiliche Vorgehen. Die politischen Kneipen in der Weimarer Republik übernahmen die Tradition der Kneipenkultur der sozialdemokratischen Arbeiterbewegung, die in der letzten Hälfte des Deutschen Reiches entstand. Deshalb kann man unter dem Gesichtspunkt der Verbindung der Kneipen mit Politik auf eine Kontinuität von dem Kaiserreich zu der Weimarer Republik hinweisen. In der Weimarer Zeit hatte allerdings nicht nur die SPD, sondern auch die KPD und die NSDAP, also die nach dem Ersten Weltkrieg gegründeten Massenparteien, eigene Kneipen/Lokale errichtet, sodass sich die Kneipenkultur politisch polarisierten und diese Tendenz am Ende der Weimarer Republik viel größer wurde. Auf der anderen Seite hatten die politischen Kneipen im Kaiserreich als „Versteck“ funktioniert, damit man der Beaufsichtigung und der Unterdrückung der Obrigkeiten entkommen konnte, während in der Weimarer Zeit sie zum „Gefechtsstand“ im Arbeiterviertel für Überfälle auf den Gegner oder die Propaganda auf den Straßen geworden waren. Die politischen Kneipen, die öfter in der Umgebung aneinander anstoßen, waren zweifellos ein symbolisches Dasein für den politischen Alltag in der Endphase der Weimarer Republik, der durch die politische Gewalt wie Zusammenstöße und Überfälle auf der Straße charakterisiert war. Alles in allem war in der Weimarer Zeit die Beziehung der Kneipen mit der Politik sehr kompliziert geworden, da zusätzlich zum „vertikalen“ Gegensatz im Kaiserreich zwischen den Obrigkeiten und den Arbeiter der „horizontale“ Gegensatz zwischen den politischen Parteien hinzukam
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