All 3,282,994 Page 24/328,300
-
2025
Abstract
The Reissner–Weyl–Nordström (RWN) spacetime of a point nucleus features a naked singularity for the empirically known nuclear charges Ze and masses
$$M = A(Z,N)m_{\textrm{p}}$$
M
=
A
(
Z
,
N
)
m
p
, where
$$m_{\textrm{p}}$$
m
p
is the proton mass and
$$A(Z,N)\approx Z+N$$
A
(
Z
,
N
)
≈
Z
+
N
the atomic mass number, with Z the number of protons and N the number of neutrons in the nucleus. The Dirac Hamiltonian for a test electron with mass
$$m_{\textrm{e}}$$
m
e
, charge
$$-\,e$$
-
e
, and anomalous magnetic moment
$$\mu _a (\approx -\, \frac{1}{4\pi }\frac{e^3}{m_{\textrm{e}}c^2})$$
μ
a
(
≈
-
1
4
π
e
3
m
e
c
2
)
in the electrostatic RWN spacetime of such a “naked point nucleus” is known to be essentially self-adjoint, with a spectrum that consists of the union of the essential spectrum
$$(-\,\infty ,-\,m_{\textrm{e}}c^2]\cup [m_{\textrm{e}}c^2, \infty )$$
(
-
∞
,
-
m
e
c
2
]
∪
[
m
e
c
2
,
∞
)
and a discrete spectrum of infinitely many eigenvalues in the gap
$$(-\,m_{\textrm{e}}c^2,m_{\textrm{e}}c^2)$$
(
-
m
e
c
2
,
m
e
c
2
)
, having
$$m_{\textrm{e}}c^2$$
m
e
c
2
as accumulation point. In this paper, the discrete spectrum is characterized in detail for the first time, for all
$$Z\le 45$$
Z
≤
45
and A that cover all known isotopes. The eigenvalues are mapped one-to-one to those of the traditional Dirac hydrogen spectrum. Numerical evaluations that go beyond
$$Z=45$$
Z
=
45
into the realm of not-yet-produced hydrogenic ions are presented, too. A list of challenging open problems concludes this publication.- Book : ()
- Pub. Date : 2025
- Page :
- Keyword :
-
2025
AbstractPlutonium was discovered and first synthesized in the early 1940's. Several isotopes of plutonium are used in nuclear technologies, 238Pu for heat generation and 239Pu for energy production and weapons. Both isotopes emit alpha particles, which pose a significant radiation hazard when incorporated into the body. Alpha particles emitted during 239Pu decay deposit energy along a very short path in biological tissues (≈45 μm in soft tissues). Thus, defining the anatomical locations of these deposits is essential to identify the cells at risk of radiation damage and potential malignant transformation. Bone is a primary site for plutonium deposition and retention. Plutonium exposures are associated with increases in osteogenic cancers. Plutonium is preferentially deposited on endosteal and endocortical bone surfaces, particularly those surrounded by red versus yellow bone marrow. Red marrow is more vascularized with a sinusoid network, while yellow marrow is largely a closed capillary system. Cancellous bone in red marrow sites has greater bone turnover rates and relatively more plutonium‐related bone cancers than in yellow marrow sites. The relationships of plutonium deposits in bone and potential alpha particle exposures to cells that include osteoclasts, reversal cells, canopy cells, osteoblasts, bone lining cells, and osteogenic progenitors of the basic multicellular unit during bone modeling and remodeling are reviewed. Differences in distributions of 239Pu versus naturally occurring tumors in humans and experimental animals are noted. This review emphasizes the importance of the anatomical locations of plutonium deposition and retention in the skeleton and the potential relative radiation risks from alpha particles to bone cells and their progenitors.- Book : ()
- Pub. Date : 2025
- Page :
- Keyword :
-
2025
The article describes a clinical case of recurrent retroperitoneal liposarcoma with a rare type of distant metastasis in a patient undergoing surgical and chemotherapy treatment in Cancer Center No. 1 (branch of Yudin City Clinical Hospital) since May 2021. The patient's medical history and computed tomography (CT) results were analyzed. The use of CT remains an extremely important stage in the examination of patients with retroperitoneal liposarcoma for assessing local prevalence, identifying distant secondary lesions, including ones to soft tissues.- Book : 105(4)
- Pub. Date : 2025
- Page : pp.202-207
- Keyword :
-
2025
In this study, we employed the M-truncated fractional singular manifold
meth?od to analytically address the (2+1)-dimensional M-truncated fractional
Burgers equation. This approach involves reformulating the original
fractional differen?tial equation into a more tractable form through the
introduction of a singular manifold. This transformation simplifies the
problem and often leads to analytical solutions. We derive a general
solution expressed in terms of arbitrary functions, which enables us to
accommodate variations in system parameters or initial condi?tions. This
results in a versatile expression that captures a broad spectrum of
pos?sible solutions, providing a framework for analyzing the dynamics of
kink waves in the relevant fractional differential models. We also construct
multiple kink wave solutions, offering analytical representations of kink
wave behavior within these models. Notably, our findings revert to
well-established results when the fractional order is set to one, thereby
affirming the consistency of this method with existing theories and
validating our approach.- Book : 29(1 Part A)
- Pub. Date : 2025
- Page : pp.337-345
- Keyword :
-
2025
Background/Objectives: Prostate cancer (PC) is the most common non-cutaneous cancer in men globally, and one which displays significant racial disparities. Men of African descent (AF) are more likely to develop PC and face higher mortality compared to men of European descent (EU). The biological mechanisms underlying these differences remain unclear. Long non-coding RNAs (lncRNAs), recognized as key regulators of gene expression and immune processes, have emerged as potential contributors to these disparities. This study aimed to investigate the regulatory role of lncRNAs in localized PC in AF men relative to those of EU and assess their involvement in immune response and inflammation. Methods: A systems biology approach was employed to analyze differentially expressed (DE) lncRNAs and their roles in prostate cancer (PC). Immune-related pathways were investigated through over-representation analysis of lncRNA–mRNA networks. The study also examined the effects of vitamin D supplementation on lncRNA expression in African descent (AF) PC patients, highlighting their potential regulatory roles in immune response and inflammation. Results: Key lncRNAs specific to AF men were identified, with several being implicated for immune response and inflammatory processes. Notably, 10 out of the top 11 ranked lncRNAs demonstrated strong interactions with immune-related genes. Pathway analysis revealed their regulatory influence on antigen processing and presentation, chemokine signaling, and ribosome pathways, suggesting their critical roles in immune regulation. Conclusions: These findings highlight the pivotal role of lncRNAs in PC racial disparities, particularly through immune modulation. The identified lncRNAs may serve as potential biomarkers or therapeutic targets to address racial disparities in PC outcomes.- Book : 16(2)
- Pub. Date : 2025
- Page : pp.229-229
- Keyword :
-
2025
- Book : 181()
- Pub. Date : 2025
- Page : pp.105619-105619
- Keyword :
-
2025
Although Pakistan's economy depends heavily on the livestock industry, animal health is greatly impacted by tick infestation and illnesses spread by ticks. This study evaluated the morphological traits, risk factors, and prevalence of ticks in four districts within the Sargodha Division. Between February and June 2021, 1,067 ruminants (cows, buffaloes, goats, and sheep) from 40 farms were watched. The ITS-2 nuclear gene (750 bp) in 10 tick species was the object of PCR detection. The total infestation rate was 32.10%, with Khushab having the lowest percentage (24.71%) and Mianwali having the highest (54.44%). Goats (16.41%), sheep (27.38%), buffaloes (33.73%), and cows (41.5%) were the most affected species. Male buffaloes (59.37%) were more infected than females (33.58%), while female cows (45.10%) were more infested than males (31%). The distribution of ticks differed by species and sex; in cows and buffaloes, the most afflicted regions were the udder and tail, respectively. Ticks were mostly detected in the ears of sheep and goats and concentrated on the testicles of males. The major risk factors were the summer season, inadequate waste clearance, dogs afflicted with ticks, communal living, grazing systems, and poor tick control techniques. According to morphological studies, there is just one soft tick species, Ornithodoros erraticus, and hard ticks from the genera Rhipicephalus, Hyalomma, and Ixodes. Four tick species had positive bands (750 bp) validated by PCR testing. The study emphasizes the necessity for efficient tick management methods by highlighting the epidemiological implications of species, sex, and tick dispersion patterns in infection rates.- Book : 13(02)
- Pub. Date : 2025
- Page : pp.217-229
- Keyword :
-
2025
Column O/N2 ratio (∑O/N2), a physical quantity representing thermospheric disturbances, is influenced by solar extreme ultraviolet radiation flux (QEUV) changes. Investigating the correlation between these two factors is essential for understanding the evolution of the thermosphere. This study examines the correlation and periodic variations of ∑O/N2 and QEUV across different phases of solar activity, using data from the Global Ultraviolet Imager (GUVI) spanning from 2002 to 2022. A correlation analysis reveals a positive relationship between ∑O/N2 and QEUV. The function fitting results show that the magnitude of changes in ∑O/N2 due to QEUV variations is approximately 30% of the mean ∑O/N2. A wavelet analysis reveals their coherence in periodic components of 27-day, annual, and 11-year periods. These results are significant for studying the Sun–Earth coupling mechanism and understanding the impact of space weather on the thermosphere.- Book : 17(4)
- Pub. Date : 2025
- Page : pp.574-574
- Keyword :
-
2025
Non-centrosomal microtubule-organizing centers (ncMTOCs) are important for the function of differentiated cells. Yet, ncMTOCs are poorly understood. Previously, several components of the nuclear envelope (NE)-MTOC have been identified. However, the temporal localization of MTOC proteins and Golgi to the NE and factors controlling the switch from a centrosomal MTOC to a ncMTOC remain elusive. Here, we utilized the in vitro differentiation of C2C12 mouse myoblasts as a model system to study NE-MTOC formation. We find based on longitudinal co-immunofluorescence staining analyses that MTOC proteins are recruited in a sequential and gradual manner to the NE. AKAP9 localizes with the Golgi to the NE after the recruitment of MTOC proteins. Moreover, siRNA-mediated depletion experiments revealed that Mbnl2 is required for proper NE-MTOC formation by regulating the expression levels of AKAP6β. Finally, Mbnl2 depletion affects Pcnt isoform expression. Taken together, our results shed light on how mammals post-transcriptionally control the switch from a centrosomal MTOC to an NE-MTOC and identify Mbnl2 as a novel modulator of ncMTOCs in skeletal muscle cells.- Book : 14(4)
- Pub. Date : 2025
- Page : pp.237-237
- Keyword :
-
2025
- Book : ()
- Pub. Date : 2025
- Page :
- Keyword :
