bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of Centralized Heating Monitoring System Based on Wireless Sensor Networks
Authors: Jiang Xiangting , Lv Yaojun , Yan Haoran
Published: March 2022

Current centralized heating monitoring system has realized the collection and control of working condition data in heating power stations, but there are still some shortcomings, such as the inability to collect data on the working conditions of user sides, and the inability to meet the further demand of heating enterprises for the refinement of heating network monitoring data. A wireless sensor network is a fully distributed sensor system with no central node, which can intensively deploy many sensor nodes to monitoring area through random placement, and integrates sensors, data processing and communication modules to form a self-organized network system. Therefore, in order to realize the intelligence of heating system and improve the flexibility of node data collection, the monitoring system can use wireless sensor network technology to realize wireless collection of node data, and display the collected data on a man-machine interface in real time. On the basis of research results from previous scholars, this paper expounds the research status and significance of centralized heating monitoring system design, elaborates the development background, current status and future challenges of wireless sensor network technology, introduces the methods and principles of wireless network communication protocol and heating and heat balance flow analysis, proposes a structural model of a centralized heating monitoring system based on wireless sensor networks, carries out the design of perception and convergence nodes, analyzes the layout of wireless sensor networks, explores the design scheme of centralized heating monitoring system based on wireless sensor networks, conducts the hardware and software design of the monitoring system, implements the software testing and hardware debugging of the centralized heating monitoring system, and finally discusses the relationship between data transfer related tasks and task scheduling. The study results show that the application of the centralized heating monitoring system based on the wireless sensor networks can not only more conveniently monitor, control and manage the entire heating networks, but also make full use of the centralized monitoring and quantitative management functions of the wireless sensor networks. This achieves dynamic tracking and monitoring of heating operation, real-time diagnosis of hidden dangers in heating operation, and safe, normal and energy-saving operation of the centralized heating system. The study results of this paper provide a reference for further researches on the design of centralized heating monitoring system based on wireless sensor networks.
Acupoint Catgut‐Embedding Therapy Inhibits NF‐κB/COX‐2 Pathway in an Ovalbumin‐Induced Mouse Model of Allergic Asthma
Authors: Teng Fangzhou , Ma Xuedong , Cui Jie , Zhu Xueyi , Tang Weifeng , Wang Wenqian , Wuniqiemu Tulake , Qin Jingjing , Yi La , Zong Yuting , Liu Chengyong , Wang Shiyuan
Published: March 2022

Allergic asthma is associated with T helper (Th) 2 cell‐biased immune responses and characterized by the airway hyperresponsiveness (AHR). Studies have shown that the acupoint catgut‐embedding therapy (ACE) has a therapeutic effect on allergic asthma. However, the relevant mechanism is poorly understood. In present study, female BALB/c mice were sensitized and challenged with ovalbumin (OVA) to establish a model of allergic asthma. AHR was evaluated by using airway resistance (RL) and lung dynamic compliance (Cdyn). Airway inflammation and mucus hypersecretion were observed by HE and PAS staining. Inflammatory cells were counted, and related cytokines in bronchoalveolar lavage fluid (BALF) were detected by enzyme‐linked immunosorbent assay (ELISA). Pulmonary group 2 innate lymphoid cell (ILC2s) proportions were analyzed by flow cytometry. The expression of nuclear factor κB (NF‐κB) and cyclooxygenase‐2 (COX‐2) was detected by immunostaining. Our results showed that OVA induction resulted in a significant increase in RL, accompanied by a significant decrease in Cdyn. The levels of interleukin‐ (IL‐) 4, IL‐13, OVA‐specific IgE in BALF, and the percentage of ILC2 in the lungs were markedly increased accompanied by a significant decreased in interferon‐γ (IFN‐γ). Furthermore, the expressions of p‐NF‐κB p65 and COX‐2 in airways were significantly upregulated. After ACE treatment, the indicators above were significantly reversed. In conclusion, ACE treatment inhibited the secretion of Th2 cytokines and the proliferation of ILC2s in the lungs, thereby dampening the inflammatory activity in allergic asthma. The underlying mechanism might be related to the inhibition of NF‐κB/COX‐2 pathway.
The Impact of Critical Flutter Velocity in Composite Wind Turbine Blade with Prebend Condition
Authors: Kumar H. S. Sunil , Jagadeesh K. R. , Anand R. B. , Rangaswamy T. , Salyan Srikanth , Solomon Jenoris Muthiya , Arockia Dhanraj Joshuva , Isaac Joshua Ramesh Lalvani Joshua Stephen Chellakumar
Published: March 2022

The present work focuses on the effect of flutter in prebend 100 m horizontal axis wind turbine blade (HAWT) within the stability limits. The study was carried out with an advanced beam model for idyllic structure in a DU-97-W-300 cross-sectional area. A Galerkin type of approach has been applied to derive the equations, and the analysis was performed using a standard FEA code which involves the PK method and double lattice method for calculating flutter solution and aerodynamic loads respectively. The results reveal the significance of inducing prebending to improve the stability of the blade structures, and hence, the flutter velocity has moved from 11 m/s to 23 m/s. Furthermore, the output highlights the effect of prebending on the structural stability and also the flutter limit was found to be lengthened.
Effect of Different MPTP Administration Intervals on Mouse Models of Parkinson’s Disease
Authors: Ma Yuanyuan , Rong Qiongwen
Published: March 2022

Objective. To research the effect of different 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP) administration intervals on the behavior and pathology of mouse models of Parkinson’s disease. Methods. Eighteen C57 male mice were divided into a control group, subacute model group, and chronic model group (6 mice per group). Animal models of Parkinson’s disease were built according to MPTP administration. The behavior of mice was determined through an open‐field test and pole test. Tyrosine hydroxylase expression in brain tissues was checked by immunohistochemistry and western blot. Result. In the open‐field test, the total activity distance in the chronic model group (1271.05 ± 207.93 cm) was reduced significantly compared with that of the control group (1964.21 ± 379.77 cm), while the distance had no significant differences in the subacute model group (1950.57 ± 273.54 cm). At the same time, the number of times the mice crossed the center grid in the chronic model group (3.17 ± 1.17) was reduced compared with that in the control group (11.67 ± 6.65), while there were few differences in the subacute model group (9.33 ± 2.81). In the pole test, the climbing time (8.49 ± 1.44 s) and total rest time (103.64 ± 26.57 s) of mice in the chronic model group were longer than those in the control group, respectively (4.31 ± 0.70 s, 45.21 ± 14.36 s), while there were no significant differences in the subacute model group (4.51 ± 0.48 s, 52.44 ± 25.98 s). Besides, compared with the control group, TH expression in the subacute model group and chronic model group was reduced notably, and the changes of TH expression in the chronic model group were more significant. Conclusion. There is a little loss of midbrain dopaminergic neurons in the subacute Parkinson’s disease mouse models induced by continuous MPTP administration, but there is no effect on the behavior. Long interval MPTP‐induced chronic Parkinson’s disease mouse models lose a lot of dopaminergic neurons, which is accompanied by anxiety‐like behaviors in addition to motor dysfunction.
Determining the Level of Service Scale of Public Transport System considering the Distribution of Service Quality
Authors: Wang Min , Mao Baohua , Yang Yanqiang , Shi Ruijia , Huang Junsheng
Published: March 2022

In China, many cities are building themselves the transit metropolis, and the reasonable evaluation of level of service (LOS) of public transport system (PTS) is one important aspect. However, to determine the overall LOS is hard because the distribution of service in PTS is not homogeneous with regard to time and space. To address this problem, this study proposes a general framework to determine the LOS scale of PTS based on the distribution of service quality. Under the framework, two classification methods are discussed. Method 1 uses two parameters, the mean and coefficient of variation to model the distribution, and Method 2 is an existing approach that only considers mean. Then the specific use of the framework is expounded for the service attribute of crowding, and Beijing subway line LOS is evaluated. The line LOS is divided into I–IV, whose threshold is expressed as a function of mean and coefficient of variation. The results show that 57.8% of the sample points are in the most crowding level IV in morning peak hours by Method 1, but 60.9% of sample points are in a comfortable level II by Method 2, and the former is more consistent with reality. In addition, it reveals which lines and time periods need to improve the service level. The research proves the feasibility of considering the service distribution to determine the overall LOS of PTS, and it is useful for capturing more detailed information of the system performance in time and space. This research can provide an approach for evaluating and helping to improve the overall service level of PTS for public transport authorities.
Temperature Compensation of an Eddy-Current Displacement Sensor Using an Improved Sparrow Search Algorithm Method
Authors: Jiang Shanhe , Wang Dekai , Xing Xiangyu
Published: March 2022

Eddy-current displacement sensor (ECS) has been applied widely to the production of modern industry by reason of its characteristics of high sensitivity, good reliability, powerful anti-interference capacity, and noncontact measurement. However, it cannot be used when severe temperature drift occurs at high temperature. Some traditional compensation methods are difficult to achieve good performance with neglecting the nonlinearity. Hence, it is essential to propose a better method for temperature compensation. A novel temperature compensation approach for ECS problem using an improved sparrow search algorithm (ISSA) and radial basis function neural network (RBFNN) is proposed in this article. In the ISSA, a chaos strategy is introduced in the algorithm for avoiding local optimal point, and an elite opposition-based learning strategy is integrated to promote global search ability of ISSA with high efficiency. RBFNN is elected to model the temperature drift, and its parameters are determined by the proposed ISSA. The proposed method compensates the significant deterministic errors caused by temperature variation within a wide temperature range. The experimental schemes were designed to the effectiveness of the proposed method according to data fusion technology. The various test results obtained confirm the potential and effectiveness of the proposed approach compared to some other traditional temperature compensation methods presented in the literatures.
The Rate of Convergence of the SOR Method in the Positive Semidefinite Case
Authors: Dax Achiya
Published: March 2022

In this paper, we derive upper bounds that characterize the rate of convergence of the SOR method for solving a linear system of the form

G
x
=
b

, where

G

is a real symmetric positive semidefinite

n
×
n

matrix. The bounds are given in terms of the condition number of

G

, which is the ratio

κ
=
α
/
β

, where

α

is the largest eigenvalue of

G

and

β

is the smallest nonzero eigenvalue of

G

. Let

H

denote the related iteration matrix. Then, since

G

has a zero eigenvalue, the spectral radius of

H

equals 1, and the rate of convergence is determined by the size of

η

, the largest eigenvalue of

H

whose modulus differs from 1. The bound has the form

η

2

≤
1
−
1
/

κ
c

, where

c
=
2
+

log

2

n
.

The main consequence from this bound is that small condition number forces fast convergence while large condition number allows slow convergence.
Polyimide-Based Materials for Lithium-Ion Battery Separator Applications: A Bibliometric Study
Authors: Hu Huakun , Xue Wendong , Jiang Peng , Li Yong
Published: March 2022

Polyimide (PI) has excellent thermal stability, high porosity, and better high-temperature resistance. It has the potential to become a more high-end separator material, which has attracted the attention of the majority of researchers. This review is aimed at identifying the research progress and development trends of the PI-based material for separator application. We searched the published papers (2012–2021) from the WOS core collection database for analysis and analyzed their research progress and development trend based on CiteSpace text mining and visualization software. The analysis shows that the PI-based composite separator material is a research hotspot in the future and the combination of nanofiber and cellulose materials with PI is also an important research direction in the future.
An Empirical Analysis of the Correlation between Listed Companies’ Financial Shared Services and Corporate Innovation Performance: Based on the Empirical Data of A-Share Listed Companies
Authors: Yang Ying , Cui Wenqin , He Jinfang
Published: March 2022

With the rapid development of information technology, the financial sharing service is a new type of financial management that saves human capital, changes management concepts, improves management efficiency, and improves the internal control environment by centralizing the simple and repetitive work of enterprises. Financial shared services will strengthen the innovation capabilities of enterprises in terms of financial personnel, management personnel, and internal control environment. Therefore, in order to explore whether the new management model of financial shared services can bring about an improvement in the level of corporate innovation, this article starts from the perspective of financial shared services, takes A-share listed companies as the research sample, and uses the DID regression model to empirically analyze the relationship between financial shared services and the correlation between corporate innovation performance. The results of the research show that implementing financial sharing service can significantly improve enterprise innovation performance.
Effect of Transumbilical Single-Port Laparoscopic-Assisted Duhamel Operation on Serum CRP and IL-6 Levels in Children with Hirschsprung’s Disease
Authors: Wang Miao , Pang Wenshuai , Zhou Lixia , Ma Jiansu , Xie Shasha
Published: March 2022

Objective. To explore the clinical intervention effect of transumbilical single-port laparoscopic-assisted Duhamel operation on children with Hirschsprung’s disease (HD) and to analyze the effect of treatment on children with serum C-reactive protein (CRP) and interleukin-6 (IL-6) effects. Methods. Retrospectively select 80 children with HD who underwent surgery in our hospital from May 2017 to May 2020 as the research subjects and they are classified as group A according to the difference of the children’s surgical procedures (receiving transumbilical single-port laparoscopic-assisted Duhamel surgery, 40 cases) and group B (receiving conventional laparoscopic surgery, 40 cases), compare the perioperative period (operating time, intraoperative blood loss, surgical posthospitalization, and postoperative gastrointestinal function recovery time), early postoperative complications (perianal dermatitis, urinary retention, enterocolitis, and anastomotic leakage), and late postoperative complications (anastomotic stenosis, dirty stool, recurrence of constipation, and enterocolitis), compare the differences in the levels of CRP and IL-6 between the two groups of children before and after the operation, and conduct a 1-year follow-up of the two groups of children to compare the long-term defecation status. Results. The surgical time of children in group A, postoperative hospitalization time, and postoperative gastrointestinal function recovery time were significantly shorter than those of group B, and the differences between groups were statistically significant (

P
<
0.05

). A group of patients: the total incidence of postearly complications was 5.00% lower than 22.50% (

P
<
0.05

) in group B (

P
<
0.05

), and the total incidence of previous complications after group A of patients was 10.00% lower than 27.50% of group B (

P
<
0.05

). The two groups of serum CRP and IL-6 in two groups were not statistically significant (

P
>
0.05

), and the serum CRP and IL-6 levels of children in group A after surgery were 3 days. It is obviously lower than those in group B, and the differences between groups have statistical significance (

P
<
0.05

). At 1 month after surgery, the average bowel movement time in group A is significantly lower than those of group B (

P
<
0.05

); during the 1–12 months, the difference between the defecation frequency group of the group A and group B did not have statistically significance (

P
>
0.05

). Conclusion. Transumbilical single-port laparoscopic assistant Duhamel operation of HD has a good intervention effect, compared to traditional laparoscopic surgery, the operation time, postoperative hospitalization time, and postoperative gastrointestinal function recovery time, and also help to reduce postoperative near-long complications The incidence improves the stress reactions and long-term defecation functions in children.
Digital Gangrene: An Unusual Manifestation of Non-Hodgkin Lymphoma
Authors: Momen Majumder Muhammad Shoaib , Ahmed Shamim , Haque Tajkia , Haq Syed Atiqul , Chakravarty Saumitra , Shahin Md. Abu , Osmany Din-E-Mujahid Mohammad Faruque , Rasker Johannes J.
Published: March 2022

Background. Non-Hodgkin lymphomas (NHLs) comprise a group of haematologic malignancies with different histologic subtypes. The clinical picture varies from indolent to aggressive presentation and nodal (lymphadenopathy) to extranodal (central nervous system, gastrointestinal, cutaneous plaque, or ulcer) involvement. Digital gangrene is seldom reported. Here, we describe a patient with pain and blackening of all fingers and toes as presenting symptoms of NHL. Case Presentation. A 32-year-old male weaver had been smoking three to five cannabis-containing cigarettes daily for about ten years and methamphetamine four to five tablets daily for five years. He had no history of Raynaud’s phenomenon, fever, cough, weight loss, skin rash, joint pain, and atherogenic or thrombogenic risk factors. We found normal blood pressure and absent peripheral pulses in arms and legs, dry gangrene of all fingers and toes, generalized lymphadenopathy, and hepatomegaly with ascites. The chest X-ray was normal, as were blood sugar, lipid profile, and hepatic and renal function. Rheumatoid factor, antinuclear and antiphospholipid antibodies, C-ANCA and P-ANCA, hepatitis B and C, and HIV were negative. CT abdomen revealed hepatosplenomegaly with multiple intra-abdominal lymphadenopathies. The peripheral angiogram showed 90-99% stenosis of radial and dorsalis pedis arteries with normal proximal vessels. Diagnosis of non-Hodgkin lymphoma was confirmed by histopathology of cervical lymph node (diffuse type), immunohistochemically subtyped as peripheral T cell lymphoma (not otherwise specified). The digital ischemia worsened despite cessation of cannabis and methamphetamine and starting CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisolone) treatment, making amputation necessary. Conclusion. We present, to our knowledge, the first report of peripheral T cell lymphoma, NOS presenting with gangrene in all digits complicated by methamphetamine and cannabis abuse. This uncommon vascular manifestation of non-Hodgkin lymphoma may cause a diagnostic dilemma and delayed initiation of treatment.
Intelligent Resource Allocation for Ultradense Networks Based on Improved Reinforcement Learning
Authors: Ye Zhou
Published: March 2022

The urgent need of high-quality mobile services and improved user experience has driven to develop high-capacity mobile network system. To achieve this goal, ultradense network (UDN) has been widely considered as one of the promising solutions that significantly expand the network capacity. However, as the communication resources and the number of links per unit area are extremely densified within UDN, efficient and high-quality scheduling and resource allocation for UDN become challenging. Even worse, the complex environment of UDN limits the direct adoption of traditional allocation schemes to UDN. In this manuscript, the author is going to propose an efficient resource allocation algorithm for UDN based on deep reinforcement learning. First, the author presents the resource allocation strategies in cellular network server based on double Q-learning. Then, the author optimizes the algorithm by pruning redundant model weights and making a tradeoff between computational complexity and performance to meet the requirements of low latency and limited computing costs. The experiment and simulation results show that the pruning algorithm effectively reduces 50% model parameters. The UDN allocation performance is still acceptable as the proposed algorithms save up to 50% complexity.
A Versatile and Ubiquitous IoT-Based Smart Metabolic and Immune Monitoring System
Authors: Arunkumar N. , Pandimurugan V. , Hema M. S. , Azath H. , Hariharasitaraman S. , Thilagaraj M. , Govindan Petchinathan
Published: March 2022

In the present medical age, the focus on prevention and prediction is achieved using the medical internet of things. With a broad and complete framework, effective behavioral, environmental, and physiological criteria are necessary to govern the major healthcare sectors. Wearables play an essential role in personal health monitoring data measurement and processing. We wish to design a variable and flexible frame for broad parameter monitoring in accordance with the convenient mode of wearability. In this study, an innovative prototype with a handle and a modular IoT portal is designed for environmental surveillance. The prototype examines the most significant parameters of the surroundings. This strategy allows a bidirectional link between end users and medicine via the IoT gateway as an intermediate portal for users with IoT servers in real time. In addition, the doctor may configure the necessary parameters of measurements via the IoT portal and switch the sensors on the wearables as a real-time observer for the patient. Thus, based on goal analysis, patient situation, specifications, and requests, medications may define setup criteria for calculation. With regard to privacy, power use, and computation delays, we established this system’s performance link for three common IoT healthcare circumstances. The simulation results show that this technique may minimize processing time by 25.34%, save energy level up to 72.25%, and boost the privacy level of the IoT medical device to 17.25% compared to the benchmark system.
Research on Spatiotemporal Association between Tourism and Transportation Based on CGS Model
Authors: Xu Yanan , Qin Jianxin , Wu Tao , Liu Bo , Xia Yuanping
Published: March 2022

Tourism and transportation generally have an inseparable association. However, there are still many limitations in the existing research on it. For example, most scholars only adopt one single model method, which fails to consider geospatial elements. Moreover, some researchers simply use socioeconomic data for analysis and research and ignore the solid spatial characteristics between tourism and transportation, which leads to deviations in the results. To solve these problems, this article proposed a spatiotemporal association model by comprehensively using coupling coordination degree, gravity center model, and spatial coincidence degree. Based on the tourism economic and attraction spatial data, and the transportation and its network spatial data, the association between tourism and transportation can be revealed by the proposed model. This study conducted a quantitative analysis on the tourism and transportation industry in Jiangxi Province, China, from 2005 to 2019, and the results show that: (1) the coupling coordination degree of tourism and transportation increases year by year; (2) the change in gravity center of tourism and transportation is subtle. The mean value of spatial overlap is 80.33 km, while the mean value of inter-annual variation consistency is 0.56; (3) the spatial coincidence degree of tourism and transportation in Jiangxi Province indicates a steady upward trend and reaches 0.78 in 2019; and (4) based on the evolution trend in the coupling coordination degree, gravity center coupling model, and spatial coincidence degree of tourism and transportation, it can be seen that the slopes of their trend functions are similar and consistent—the slopes are 0.0239, 0.0253, and 0.0319, respectively—and the standard deviation of the slopes of the three is only 0.000018.
The Difficulty of Appraisal of Streptokinase Treatment of Myocardial Infarction
Authors: Verstraete M.
Published: March 2022

Considerable advances have been made in clinical pharmacology of late, permitting more precise evaluation of new drugs. This must be taken into account in assessing the thrombolytic therapy of acute myocardial infarction. Clinical trials necessitate control groups, which must in volve a sufficiently large number of patients so that differences are not due to chance. To be valid, the groups must be strictly comparable. It is essential to define precisely criteria for admission and contraindications, if possible stratifying the patients, since the final evaluation must include all patients according to the treatment originally allocated. For recent myocardial infarction, it is important to compare thrombolytic therapy with the best treatment currently available, the patients being randomly allocated to these alternatives. However, it is not clear whether the best current treatment is anticoagulation, polarizing solutions (combining glucose, insulin and potassium), prophylactic antiarrhythmic drugs (procainamide, lignocaine) or β-adrenergic inhibitors (propranolol), and therefore which to use in comparison. The trend to coronary care units already has shown a reduction in mortality, perhaps necessitating evaluation of thrombolytic therapy only in such units. If thrombolysis finds a place in the management of myocardial infarction, treatment must start within the first hours following onset of symptoms. This increases the likelihood that patients diagnosed erroneously also will be treated with thrombolytic agents. Reassurance is needed that such treatment is harmless in these circumstances. Lastly, the statistical interpretation of the value of thrombolytic therapy must be regarded as a ‘two-tailed’ situation.
The Diurnal Dynamics of DNA Synthesis in Cells of the Thoracic Duct Wall
Authors: Malyuk V.I. , Fomicheva Valentina M.
Published: March 2022

The relative number of DNA-synthetizing fractions from endothelial and muscle cells of the thoracic duct in mature albino rats increased in the late afternoon and early morning hours. In fibroblasts, the individual variability of the thymidine-3H labelling index considerably exceeded the theoretically expected occasional value.
Influence of Body Posture on Leg Blood Flow
Authors: Amery A. , Bossaert H. , Deruyttere M. , Vanderlinden L. , Verstraete M.
Published: March 2022

The influence of body posture on limb blood flow was studied in normal subjects, in patients with arterial insufficiency of the lower limbs and in hypertensive patients using the 133Xe local clearance technique. Muscle blood flow in the three groups, measured at rest or after ischaemia provoked by cuff, with or without exercise, was significantly lower in the erect position (sitting or standing) compared to the recumbent position. Both in normal subjects and in patients with arterial insufficiency muscle blood flow, computed from the disappearance rate of 133Xe, injected together with histamine into the tibialis anterior muscle, was not significantly different in the recumbent and sitting position. On the contrary, in both groups of subjects the skin blood flow computed from the disappearance rate of 133Xe, injected together with histamine intradermally on the dorsum of the feet, was significantly higher in the sitting position than in the recumbent position. These results are discussed in connection with the relief of pain observed by certain patients with arterial insufficiency when they dangle their legs.
Antagonism by PGF2α of the Vasodilation Induced by PGE1, PGE2 and PGA1 in the Canine Uterus
Authors: Clark Kenneth E. , Brody Michael J.
Published: March 2022

Prostaglandins appear to play an important role in a number of reproductive processes. The present study was designed to determine if the vasodilator action of prostaglandins of the A and E series on uterine vascular smooth muscle was mediated via a receptor and if PGF2α could compete for this same receptor. The data demonstrate that PGF2α which by itself has no uterine vascular effect, can produce a parallel shift in the dose-response curves for certain vasodilator prostaglandins. This action, which suggests competitive antagonism, may well play a role in regulating blood flow in the nonpregnant uterus.
Potassium Relaxation of Vascular Smooth Muscle from Spontaneously Hypertensive Rats
Authors: Webb Clinton , Bohr David F.
Published: March 2022

Helical strips of tail artery from spontaneously hypertensive (SHR) and Kyoto Wistar normotensive rats (WKY) were observed to relax in response to potassium after contraction induced by norepinephrine in potassium-free solution. Helical strips from SHR consistently showed greater relaxation in response to the addition of potassium than did those from WKY. The amplitude of potassium-induced relaxation is believed to be an index of the activity of electrogenic sodium-potassium transport and hence of sodium-potassium ATPase. Thus, the sodium-potassium ATPase activity of SHR vascular smooth muscle is increased as compared to WKY. This interpretation is supported by the observation that ouabain eliminated potassium-induced relaxation in both SHR and WKY strips. Potassium-induced relaxation in SHR was more sensitive to ouabain inhibition than in WKY. Relaxation induced by potassium in SHR and WKY strips was also shown to vary with: (1) the length of incubation in potassium-free solution, and (2) the concentration of potassium added back. The results of these experiments on potassium-induced relaxation serve as evidence that SHR have either an increased intrinsic sodium-potassium ATPase activity, or an enzyme activity that has been stimulated to a greater degree by an elevated intracellular sodium concentration which resulted from the incubation in potassium-free solution.
Catecholamines in the Vasculature of the Rat and Rabbit: Dopamine, Norepinephrine, Epinephrine
Authors: Head R.J. , Hempstead J. , Berkowitz B.A.
Published: March 2022

A highly sensitive radioenzymatic assay for the measurement of catecholamines in small blood vessels was applied to the measurement of the levels of norepinephrine (NE), dopamine (DA) and epinephrine (E). The results showed the presence of NE, E and DA in all segments of rat or rabbit vascular tissue analyzed. The predominant catecholamine in the vasculature from both species was NE, and the contents of E and DA were similar for most vessels. Unexpectedly large concentrations of E were associated with rabbit blood vessels.
Control of Coronary Flow by Local Factors during Hypoxia with and without a Fall in O2 Consumption
Authors: Stowe David F.
Published: March 2022

The primary objectives were: (1) to examine if vasodilatory amounts of metabolites are released during moderate as well as during severe hypoxia of donor hearts; (2) to compare vasodilation to hypoxia with infusion of adenosine, and (3) to determine if metabolically induced vasodilation can be selectively reduced or abolished in order to determine the responsible metabolic factors. Pairs of isolated guinea pig hearts (n = 50) were perfused with a modified physiological saline solution by the Langendorff method. Assay hearts were also perfused with either uncorrected, anaerobic donor heart effluent or with effluent in which Po2, Pco2 and pH were corrected to control perfusate levels. When donor hearts were made moderately hypoxic (effluent Po2 – 45 ± 5 Torr; myocardial oxygen consumption – MVO2-unchanged) and assay hearts were perfused at constant pressure with gas-corrected donor effluent, we saw no change in assay flow. But when adenosine was infused to produce the same flow increase observed during mild hypoxia in donor hearts, the assay heart conductance rose to 38 ± 7%. In contrast, when donor hearts were made severely hypoxic (effluent Po2 = 34 ± Torr; MVO2 reduced by 53 ± 6% and assay hearts were perfused at constant flow with corrected donor effluent), we found a 60 ± 5 % increase in vascular conductance; this dropped to 24 ± 6% over control when adenosine deaminase was infused into the donor effluent tubing and to 5 ± 4% when theophylline was infused into assay hearts. In this bioassay study we also found that 68 ± 5% of adenosine infused into donor hearts during normoxia was removed in transit through the vasculature. Overall, our results indicate that adenosine, primarily, but perhaps also adenine nucleotides, are released in vasodilatory concentrations with severe hypoxia. However, the metabolic factors which increase coronary flow during mild hypoxia when MVO2 is not compromised could not be ascertained.
Agonist Action of Yohimbine on the Perfused Rabbit Central Ear Artery
Authors: Tayo Fola M.
Published: March 2022

The agonist action of yohimbine, an α-adrenoceptor antagonist, was studied on the perfused ear artery of the rabbit. Yohimbine, 5-hydroxytryptamine (5-HT) and noradrenaline produced concentration-dependent vasoconstnction of the central ear artery and gave EC50 values of 3.5 × 10-7, 7.5 × 10-9 and 3.0 × 10–10 M, respectively. Phentolamine significantly reduced the effects of yohimbine, 5-HT and noradrenaline, and gave pA2 values of 8.40 (slope = 1.0), 8.60 (slope = 0.94) and 8.20 (slope = 1.04), respectively. Methysergide, a serotonergic antagonist, significantly reduced yohimbine- and 5-HT-induced vasoconstriction but failed to influence the effect of noradrenaline. Reserpine treatment induced hypersensitivity of the ear artery to yohimbine and noradrenaline but not to 5-HT. It is suggested that the agonist action of yohimbine on the ear artery may be mediated via activation of α-noradrenoceptors.
Morphological and Functional Aspects of Heart Homograft Adaptation to Hamster Cheek Pouch
Authors: Schümann K. , Henrich H. , Ley K. , Heine H.
Published: March 2022

Atrial homografts from newborn hamsters, transplanted into cheek pouches of adult Syrian golden hamsters, were studied using intravital and electron microscopy. Half of the transplants survived up to 1 year, performing spontaneous pulsatile activity. The transplants could be influenced by β-receptor activating or blocking substances applied intravenously to the host animal. For morphological analysis homografts were taken 3, 6, and 12 months after transplantation. Irregular arrangement of the myofibers occurred, and the T system was seen to be replaced by plasmalemmal and sub-plasmalemmal vesiculations. There was some evidence for hypoxia in the grafts. Dedifferentiation of atrial cardiocytes, somehow resembling smooth muscle cells, is discussed. Despite these morphological changes the specific contractile function of the grafts was preserved.
Characterization of the Thrombin-Induced Contraction of Vascular Smooth Muscle
Authors: Haver Virginia M. , Namm Donald H.
Published: March 2022

Purified human α-thrombin induced a sustained contraction of isolated rabbit aorta and dog coronary arteries. These vascular tissues also exhibited a refractoriness towards a second thrombin exposure. The extent of tachyphylaxis exhibited by the aorta correlated with the initial concentration of thrombin and the length of time the tissue was exposed to thrombin. The thrombin-induced contraction in the aorta was not blocked by phospholipase or cyclooxygenase inhibitors, but it was inhibited in the presence of hirudin, heparin, nitroglycerin, and nitroprusside. Nitroglycerin, nitroprusside, and hirudin also inhibited the contraction in the dog coronary artery. Ca++ channel blockers did not inhibit the thrombin-induced contraction in the coronary artery, although a small inhibition was observed in Ca++-free media. In both tissues, equivalent contractile responses were obtained using equimolar quantities of β-, tetranitromethane-, and α-thrombin, even though the latter’s coagulant activity was 30-40 times that of the modified thrombins. However, if the catalytic activity of thrombin was inhibited by modification with Tos-Lys-CH2Cl, hirudin, or heparin/antithrombin III, the vasoconstrictor activity was also lost. These studies suggest that alterations of the fibrinogen-binding site do not affect the contractile activity of thrombin. The contraction may be the result of a proteolytic interaction of the active site of the enzyme with vascular smooth muscle.
The Mode of ATP-Induced Vasoconstriction in the Canine Internal Carotid Artery
Authors: Kawai Yasuaki , Ohhashi Toshio , Azuma Takehiko
Published: March 2022

The mode of the ATP-induced vasoconstriction in the internal carotid artery was studied from the physiological and pharmacological points of view. ATP caused dose-dependent vasoconstrictions in the canine internal carotid artery. The ATP-induced vasoconstriction was not affected by pretreatment with phenoxybenzamine, propranolol, atropine, cyproheptadine, or tetrodotoxin. Verapamil suppressed the contractile response. ATP produced no vasoconstriction in a calcium-free Krebs solution containing 1 mM EGTA nor augmentation of Ca2+-induced contraction in potassium-depolarized tissues. These results suggest that an increase of potential-dependent Ca2+ influx into the arterial smooth muscle may play a major role in the ATP-induced vasoconstriction.
Patterns of α-Adrenoceptor Regulation of the Vasculature
Authors: Bevan John A. , Bevan Rosemary D.
Published: March 2022

There are patterns in the distribution of the characteristics of vascular α-adrenoceptors. Sudden changes in their mechanism occur at particular sites along the main branches of the aorta; in some regional vascular beds, but not others, there is a progressive reduction in the response that can be elicited through the α-adrenoceptor; in smaller blood vessels, α- and β-adrenoceptors may be spatially separated in the vessel wall; in most blood vessels, the inner smooth muscle is more sensitive to α-agonists and more dependent on sequestered calcium than the outer. There is little support for a significant physiological role of the proposed γ-receptor.
Adrenergic and Serotoninergic Mechanisms in Human Hand Arteries and Veins Studied by Fluorescence Histochemistry and in vitro Pharmacology
Authors: Arneklo-Nobin Birgitta , Owman Christer
Published: March 2022

Isolated hand arteries and veins from healthy human subjects were tested in vitro for their contractile response to adrenergic agonists and 5-hydroxytryptamine (5-HT) under standardized conditions. This allowed for quantitative estimation of various receptor characteristics. The relative sympathomimetic potency suggested α-adrenergic receptors, which was confirmed in Schild plots following phentolamine antagonism of the response (pA2 for artery 7.57, for vein 7.75). 5-HT contracted with a relative potency approximately equal to noradrenaline and adrenaline in arteries, but only one fifth to one tenth of the catecholamine activity in veins. Ketanserin inhibited the 5-HT response in a competitive, probably also irreversible, manner in arteries (pA2 9.50, KA 8.90 × 10–7 M). In the veins, ketanserin counteracted the 5-HT-induced contraction in a noncompetitive way.
Effect of Prazosin on the Efflux of 3H-Norepinephrine and Metabolites from the Intima and Adventitia of the Rabbit Ear Artery
Authors: Parker D.A.S. , de la Lande I.S. , Thompson J.A. , Parker I.
Published: March 2022

The spontaneous and stimulation-induced (SI) effluxes of 3H-norepinephrine (3H-NE) and its metabolites from the intimal and adventitial surfaces of perfused segments of rabbit ear arteries were determined; vessels were previously incubated with 3H-NE (0.6 µM). The total SI adventitial efflux of 3H was approximately 10-fold greater than the intimal efflux, contained a higher percentage of unchanged 3H-NE (48 vs. 12%) and a lower percentage of O-methylated metabolites (17 vs. 55%); there was little difference between the percentages of deaminated catechols (35 vs. 31 %). Prazosin, at a concentration (0.24 µM) which prevented the arteries constricting during stimulation, had little effect on the composition of the SI effluxes; however, it caused 2- to 3-fold increases in the effluxes of 3H-NE and its metabolites into the lumen during the period of stimulation. This effect is attributed to the failure of the vessel wall to thicken during stimulation, thus facilitating diffusion of 3H-NE and its intra-neuronally formed metabolites across the media. Prazosin decreased the percentage of unchanged 3H-NE and increased that of the deaminated catechols in the spontaneous efflux; these effects are attributed to a direct effect of prazosin on the intra-neuronal metabolism of 3H-NE.
Effects of Chronic Beta-Aminoproprionitrile Treatment on Rat Carotid Artery
Authors: Cox Robert H. , Bashey Reza , Jimenez Sergio
Published: March 2022

The effects of chronic treatment of young rats (initially 8 weeks old) with the collagen cross-linking inhibitor, beta-aminoproprionitrile (BAPN), on arterial wall properties were studied. BAPN was added to the drinking water for 8 weeks to produce intakes of 0, 100, 200 and 400 mg/kg/day. Systolic pressure of treated animals did not increase with age as rapidly as that of untreated controls. Weight gain of treated animals was inhibited at the highest (BAPN) treatment level. Passive stiffness of isolated, cylindrical segments of carotid arteries was decreased in BAPN-treated animals in a dose-dependent manner. BAPN treatment had no significant effect on the total collagen or elastin content (hydroxyproline) of carotid arteries. Values of maximum active force development to 10 µM norepinephrine plus 75 mM K+ were decreased by BAPN treatment in a dose-dependent manner. There was no significant effect of BAPN treatment on total water content or its cellular and extracellular components in the carotid artery. The relative cell volume of carotid arteries was not altered by BAPN treatment, suggesting that the decreased force development was a characteristic of individual cells. These results suggest that BAPN treatment may decrease stiffness by altering secondary characteristics of the connective tissue matrix without affecting connective tissue content. The decreased maximum smooth muscle force development may be responsible for the blood pressure-lowering effects of BAPN.
Cardiovascular and Renal Actions of Cytochrome P-450 Metabolites of Arachidonic Acid
Authors: Proctor K.G. , Capdevila J.H. , Falck J.R. , Fitzpatrick F.A. , Mullane K.M. , McGiff J.C.
Published: March 2022

Cytochrome P-450 is the terminal oxidase of the electron transport chain in the endoplasmic reticulum. Arachidonic acid (AA) can be oxidatively metabolized by cytochrome P-450 hemoproteins to an array of compounds identified as constituents of tissues and biological fluids. Their synthesis can be manipulated by pharmacologic probes and are altered in pathophysiologic conditions. These novel eicosanoids stimulate release of peptide and steroid hormones, inhibit platelet and leukocyte aggregation, influence Na+-K+-ATPase and alter vasomotor tone. They also participate in fluid and electrolyte homeostasis, stimulus-secretion coupling, and regulation of tissue blood flow. Since these novel AA metabolites may participate in receptor-mediated signal transduction, and have been implicated in the generation of second messengers and changes in intracellular calcium, these studies have important implications for understanding basic biological mechanisms.
Role of the X and Y Chromosomes in the Female Germ Cell Line Development in the Mouse (Mus musculus)
Authors: Yamazaki Wataru , Tan Seang Lin , Taketo Teruko
Published: March 2022

Background: In eutherian mammals, the sex chromosome complement, XX and XY, determines sexual differentiation of gonadal primordia into testes and ovaries, which in turn direct differentiation of germ cells into haploid sperm and oocytes, respectively. When gonadal sex is reversed, however, the germ cell sex becomes discordant with the chromosomal sex. XY females in humans are infertile, while XY females in the mouse (Mus musculus) are subfertile or infertile dependent on the cause of sex reversal and the genetic background. This article reviews publications to understand how the sex chromosome complement affects the fertility of XY oocytes by comparing with XX and monosomy X (XO) oocytes. Summary: The results highlight 2 folds disadvantage of XY oocytes over XX oocytes: (1) the X and Y chromosomes fail to pair during the meiotic prophase I, resulting in sex chromosome aneuploidy at the first meiotic division and (2) expression of the Y-linked genes during oocyte growth affects the transcriptome landscape and renders the ooplasmic component incompetent for embryonic development. Key Message: The XX chromosome complement gives the oocyte the highest competence for embryonic development.
Relevance of Cardiovascular Risk Factors Screening in People Aged over 65 Years: Results from a Large French Urban Population (The CARVAR92 Study)
Authors: Pépin Marion , Hauguel-Moreau Marie , Hergault Hélène , Beauchet Alain , Rodon Christophe , Cudennec Tristan , Teillet Laurent , Dubourg Olivier , Mansencal Nicolas
Published: March 2022

Background: Cardiovascular disease is the leading cause of death and disability in older people. Traditional cardiovascular risk factors (CVRFs) still have an impact on cardiovascular risk among older people. Nevertheless, screening campaigns rarely target subjects aged over 65 years. This study aimed to assess the distribution and relevance of conventional CVRF screening in people aged over 65 years. Methods: Between 2007 and 2018, among a screening CVRF campaign in the western suburbs of Paris (32,692 subjects), we individualized 6,577 subjects aged 65 years and over. All conventional CVRFs have been systematically assessed. Results: The screening allowed to suspect hypertension in a larger proportion of subjects over 65 years compared to subjects under 65 years (27% vs. 18%, p < 0.0001). Hypertension control was higher in women compared to men but not significantly different in the age-groups (p = 0.91). Screening for diabetes mellitus was positive in 3% of older subjects and 2.4% in younger (p = 0.005). Risk assessment with dedicated score (SCORE O.P.) allowed to move toward a low-risk estimation, resulting in the diminution of intermediate risk group in women over 65 years (from 68 to 61%, p < 0.001). Conclusions: Screening CVRFs especially hypertension remains relevant in people aged over 65 years as it enables to detect unknown CVRFs in numerous subjects. Increasing awareness of CVRFs may be the first step to CVRF control, which is known to be efficient on cardiovascular mortality and functional autonomy in later life.