bluuebunny/crossref_metadata_2025_split huggingface dataset:
Investigation of the nonlinearity of PIN diode on frequency reconfigurable patch antenna
Authors: Musa Umar , Shah Shaharil Mohd , Majid Huda A , Mahadi Ismail Ahmat , Mohamad Kamal A Rahim , Yahya Muhammad Sani , Abidin Zuhairiah Zainal 
Published: September 2023

AbstractIn this work, the nonlinearity of PIN diode on frequency reconfigurable patch antenna is investigated. To perform frequency reconfiguration, the proposed design makes use of the switching capabilities of a PIN diode. The antenna has a dimension of 41 × 44 mm2 corresponding to 0.33 λ0 × 0.35 λ0, where λ0 represents the wavelength in free space at 2.4 GHz fabricated on Rogers Duroid RO3003TM material. In the OFF state of the PIN diode, a single resonance (ISM 5.8 GHz) is achieved. However, in the ON state of the PIN diode, a dual‐resonance (ISM 5.8 GHz and 2.4 GHz) is achieved. A directional and bidirectional radiation pattern can be observed in the E‐plane at 5.8 GHz and 2.4 GHz, respectively, and omnidirectional radiation patterns can be viewed in the H‐plane for both 5.8 GHz and 2.4 GHz. The gain is measured to be 4.84 dBi at 2.4 GHz and 5.87 dBi at 5.8 GHz, with total efficiencies of 91.8% and 92.5% at 5.8 GHz and 2.4 GHz, respectively. Two‐tone nonlinear measurements at 2.4 GHz and 5.8 GHz are used to evaluate the PIN diode. Several third‐order intermodulation distortion products (IMD3) frequencies are observed with input powers between 0 and 20 dBm. The IMD3 at 2.4 GHz is −36.18 dBm, while at 5.8 GHz is −47.19 dBm and the third‐order input intercept point (IIP3) of +66.65 dBm is obtained at 2.4 GHz, while +22.69 dBm at 5.8 GHz. Additionally, at 2.4 GHz, the 1‐dB gain compression (P1‐dB) could not be identified, showing that the antenna behaves linearly within the spectrum of input power. Similarly, the P1‐dB is detected at 14.8 dBm input power at 5.8 GHz. The proposed antenna works in the linear region up to an input power level of 15 dBm, where the received signal strength of the IMD3 is minimal, according to the measurement of the nonlinearity caused by the PIN diode. The nonlinearity results confirm that the active reconfigurable antenna designed and implemented in this work is suitable for use in the 2.4 GHz and 5.8 GHz bands for indoor and short‐range communication applications. Furthermore, the assessment of nonlinearity provides a deeper understanding of and helps mitigate the negative effects of nonlinearity on the proposed antenna. This measurement assists in refining biasing, selecting suitable linearization methods, improving the design, and evaluating performance at the system level. Ultimately, it enhances antenna performance and expands frequency reconfigurability by enabling optimization across multiple aspects.
Ultrafiltration in Cardiac Surgery
Authors: Walpoth B. H. , von Albertini B. 
Published: September 2023

Cardiopulmonary bypass (CPB) may result in hemodilution and volume overload. Restoration of a normal hematocrit is important for post-operative myocardial performance. Diuretics, conventionally used in the post-operative period may be ineffective due to renal impairment or lead to electrolyte imbalance.
Hollow-fiber hemofilters, made of an anisotropic polysulfone membrane (AMICON Diafilter) have been used for the ultrafiltration of blood in cardiac surgery during CPB. The hemofilter is inserted in the arterial line of the CPB. With this method ultrafiltration of the priming volume and restoration of the pre-operative hematocrit can be achieved and edema can be reversed.
In our experiments, performed in dogs (n = 5) we removed 1 L of an ultrafiltrate of plasma water in 15 minutes without hemodynamic changes or electrolyte imbalance. In the same time hematocrit increased from 19 to 29% (p < 0.05) and protein concentration from 2.7 to 5.4 g/dl (p < 0.05). Simultaneous studies with Crlabelled RBC’s demonstrated that blood volume was not significantly altered from pre CPB values during ultrafiltration, suggesting that the origin of the removed ultrafiltrate was mainly from the extravascular space.
Alpha-Stat and pH-Stat Management Techniques in Artificial Blood Oxygenators
Authors: Riley Jeffrey B. , Justison George A. 
Published: September 2023

This clinical observation relates blood pCO2, solubility, total CO2 content, oxygenator FiCO2 and ventilation rate, CO2 transfer, and respiratory quotient during hypothermic cardiopulmonary bypass.
Techniques employed to obtain the above parameters include blood gas analysis, temperature correction, gas and blood flow settings, mass spectrometry, Kelman's algorithm of the SingerHasting nomogram, and O2 and CO2 transfer calculations.
Membrane lung O2 and CO2 transfer curves demonstrate the following respiratory quotient (RQ) and CO2 blood content requirements for two common hypothermic pCO2 management techniques:

TECHNIQUE
COOLING
WARMING

pH-Stat
CO2 content increase, RQ lower than normal
CO2 content decrease, RQ much greater than normal

Alpha-Stat
CO2 content constant, RQ normal
CO2 content constant, RQ normal

Oxygen, carbon dioxide transfer versus patient temperature plots from hypothermic CPB demonstrate the perfusionist's complete control of blood CO2 content and blood pCO2.
The Effect of Methylprednisolone on Complement Activation during Cardiopulmonary Bypass
Authors: Ferries LeRoy H. , Marx James J. , Ray Jefferson F. 
Published: September 2023

A prospective randomized trial in 80 patients having heart surgery was undertaken to test the hypothesis that steroids (ST) (methylprednisolone, 30 mg/kg) would prevent or reduce complement activation during cardiopulmonary bypass (CPB) with membrane (MEM) or bubble (BUB) oxygenators. Group I patients had MEM and ST; Group II, MEM without ST; Group III, BUB and ST; Group IV, BUB without ST. Complement activation was assessed by C3a radioimmunoassay determinations obtained before, during and after CPB.
When Group I was compared to Group II, there was a significant increase in C3a generation in the presence of ST. Also, when Groups I and III combined — both with ST — were compared to Groups II and IV — both without ST — a significant increase in C3a with ST was observed. In contrast, comparing MEM to BUB (Group I vs. III or II vs. IV) no significant difference in C3a was seen.
Thus the hypothesis- that ST would prevent or reduce complement activation — was not confirmed and ST appears to actually increase complement activation. Also, MEM oxygenators were not associated with less activation of C3a than BUB oxygenators.
Factors Affecting the Activated Clotting Time
Authors: Kase Phyllis B. , Dearing James P. 
Published: September 2023

The activated clotting time (ACT) has become an important tool for monitoring the status of coagulation potential in patients undergoing cardiopulmonary bypass (CPB). Variability in results leads to confusion in interpretation of results. This study examined several CPB variables that may affect the ACT.
Samples from a controlled patient population were analyzed to evaluate relationships between blood gas analysis, hematocrit, total protein concentration and temperature at which ACT was performed and the ACT.
Duplicate samples were drawn for ACT determination (one in a 37 °c. heat block and one at room temperature). Concurrent blood gas analysis, hematocrit and total protein measurements were made.
There were significant differences between room temperature and heat block ACT during all stages of CPB but, at most times, a strong correlation existed (r ranged between .21 and .89). A positive correlation between post heparin ACT and hematocrit was shown, r = .48, while a negative correlation between post protamine ACT and hematocrit occurred, r=-.23.
Conditions under which the ACT is measured are very important for accuracy and it may be desirable to adjust a patient’s dose response based on the hematocrit.
Perfusion Considerations for Infants Weighing Ten Kilograms or Less
Authors: Hartley-Winkler Mary , Lamberti John J. , Rohrer Charlene 
Published: September 2023

Technical and philosophical perfusion considerations for infants weighing 10 kg. or less are addressed. Experience derived from 178 infants weighing from 1.7 to 10 Kg. is reviewed.
Specific topics include cannulation, priming, equipment selection, deep hypothermia vs. normothermia vs. moderate hypothermia, and special considerations in congenital cardiac surgery.
From January 1979 to December 1983, 178 consecutive infants weighing 10 Kg. or less have undergone complete surgical correction of congenital cardiac defects at the Donald Sharp—Children’s Hospital Cardiac Center in San Diego. The smallest infant weighed 1700 Gms. The average weight was 7.1 Kg. Ages ranged from one day to four years (average age 13¾ months). The overall operative mortality was 8% and was unrelated to age or weight, but was directly related to the complexity of the surgical repair. Of the eleven deaths, none were directly attributed to cardiopulmonary bypass (CPB).
The Effects of Hematocrit, Amplifier Input Impedance and Magnet Excitation Frequency on the Accuracy of Electromagnetic Flowmeters
Authors: Wagoner Philip A. 
Published: September 2023

Since the introduction of electromagnetic flowmeters, clinical users have found it necessary to contend with several problems in the accuracy of the flow signal. The cumulative results of these inaccuracies has commonly been referred to as the “hematocrit effect”.
Blood was pumped through an in vitro circuit containing a segment of canine femoral artery. The hematocrit of the blood was varied from 10% to 70%. Flow through the artery segment was measured with two clinically popular electromagnetic flowmeters employing perivascular probes. Measured flow was compared to actual flow to quantitate the “hematocrit effect”.
Both flowmeters increasingly overindicated flow as the hematocrit was decreased (r = .85, p < .01, m =- 1.51). The overindication of flow was a result of entering a manufacturer’s precalibration constant that inaccurately corrects for voltage assumed lost to erythrocyte impedance.
It is recommended that electromagnetic flowmeters not be used to evaluate coronary artery graft flow unless adequate compensation for hemodilution is made.
The amplifier input impedance and magnet excitation frequency were found to be great enough to prevent detraction from the flowmeter’s accuracy at all hematocrits studied (r > .90, p < .01).
In an ancillary study, the Carolina Medical Electronics, Inc. model 701-D Cliniflow IF™ flowmeter was found to be independent of the “hematocrit effect” (all rs > .98, all ps < .01). The Cliniflow II™ has a “user dictated” microprocessor that accurately compensates for the hematocrit effect.
Balloon Counterpulsation Together with Bio-Medicus Pump Closed Circuit Membrane Oxygenation for Left Ventricular Assist: A Case Report
Authors: Gifford David , Wheeldon Dereck , Wallwork John , Spratt Philip 
Published: September 2023

A 23-year old male was admitted at 1,093 days post cardiac transplantation in cardiac failure. Despite inotropic support and later intra-aortic balloon pumping there was a slow continued fall in cardiac output, renal function and a worsening metabolic state. The patient was then placed on extracorporeal membrane oxygenation (ECMO), consisting of a Bio-Medicus pump and Kolobow membrane oxygenator in a closed circuit configuration (without reservoir). Vascular access was by femoral artery and vein using a non-obstructive technique. Anticoagulation management consisted of a heparin infusion of 2,000 Iu/hour into a peripheral line to an ACT of 170 seconds and a prostacyclin infusion of 3ng/Kg/min. into the venous line.
Induction of ECMO was followed by a rapid hemodynamic and metabolic improvement allowing the patient to sit up, talk and eat normally. One hundred and one hours later a new donor organ was located and transplanted.
This system has much to recommend it. The equipment forms a compact module. The device functions safely with minimal perfusionist supervision. The system produces excellent offers effective short and medium term support for a range of cardiac and pulmonary disorders. hemodynamic function and offers effective short and medium term support for a range of cardiac and pulmonary disorders.
Clinical Trials of a New Low Prime Hollow Fiber Membrane Oxygenator
Authors: Dearing James P. , James David A. , Sutton Robin G. , Kratz John M. , Crawford Fred C. 
Published: September 2023

A new membrane oxygenator has been introduced by Travenol Laboratories with continued development carried out by Sarns Inc. The polypropylene hollow fibers are wound in a pattern perpendicular to the blood flow path and serve as the conduit for the ventilating gas. The membrane surface area is 1.8 M2. The device contains an integral stainless steel bellows heat exchanger and a temperature probe well built into the blood outlet. The oxygenator is held by a wire frame holder that can be mounted in any direction on the heart lung machine. A selection of various size collapsible PVC venous reservoir bags is available to meet individual patient needs. The venous inlet connector of the bag contains a temperature probe port and a connector for the cardiotomy drain line as well as a recirculation line that attaches to the oxygenator.
Twenty consenting adult patients undergoing either CABG or valve replacement were perfused using this oxygenating system. The largest patient had a BSA of 2.3 M2 while the smallest was 1.48 M2. The mean patient size was 1.92 M2. For patients 2.0 M2 or larger, a one liter reservoir bag was employed requiring a total system prime of 2.0 liters. For the remaining patients, a 500 ml bag and 1.75 liters of prime were used. In all but one case, the prime consisted of 500 ml of HES and the balance, Lactated Ringers to which was added 500 units heparin per liter of total prime. The remaining case utilized four units of fresh frozen plasma as a substitute for the HES and for 500 ml of the Lactated Ringers.
The blood gas results were very consistent and showed a very strong correlation between FiO2 setting, BSA, blood temperature and pO2. The PaCO2 was easily controlled to achieve alpha-stat by ventilating the oxygenator at the optimal ventilation rate. Results include an average PaO2 of 137 mmHg with a mean O2 transfer of 104 ml per minute and a maximum transfer of 244 ml per minute. There were no gas exchange nor acid-base problems. The heat exchanger performance was satisfactory.
The mean elevation in plasma hemoglobin was 19 mg/dl. The average decrease in platelet count was 37% while the hemodilutional hematocrit decrease was 26%. These data indicate that the oxygenator's blood handling characteristics compare favorably to other membrane oxygenators.
An In Vitro Comparison of Micro Air Passage in the Venous Reservoir Bag
Authors: Tyndal Charles M. , Berryessa Richard , Tornabene Susan P. 
Published: September 2023

The increasing use of membrane oxygenators and collapsable venous reservoir bags (VRB) imposes a concern not associated with bubble oxygenators: Venous line air. Since no defoamer is present, a VRB must rely on flow characteristics or a barrier to remove air from the venous return. The purpose of this study is to determine the air removal efficiency of seven commercially available VRBs.
Seven VRBs with clear crystaloid solution were tested for microbubble passage using an ultrasonic bubble detector at the outlet. At 5 LPM flow, 50cc of air was injected into a stopcock in the venous line. Microbubble counts were taken in six trials of each bag, and divided into three size ranges: 10–50µ, 50–100µ, and >100µ. The means and standard deviations are presented below.

VRB
10-50µ
50-100µ
>100µ

BMR1400
208.00 ± 50.29
307.00 ± 82.8
48.83 ± 18.2

BMR1900
165.83 ± 62.39
1.83± .09
0.00±0

J&J1000
147.33 ± 40.75
46.16 ± 19.98
4.33 ± 3.44

SM1300
226.16 ± 55.07
56.00 ± 22.91
11.66 ± 12.64

SM1500
332.33 ± 66.41
116.00 ± 24.30
13.33 ± 10.58

SHILEY1500
110 ± 18.54
7.33 ± 3.61
0.00±0

TERUMO1000
206.00 ± 49.68
49.80 ± 15.66
4.00 ± 5.51

There were significant differences (p<.001) between the bags in all three microbubble size ranges. Although the two best VRBs, BMR1900 and Shiley1500 had similar counts, their design is remarkably dissimilar. The BMR1900 contains a 200µ heparin coated screen and is the only VRB utilizing a barrier in the blood path.
Left Ventricular Assist with the New Bio-Pump 80
Authors: Dixon C. Martin , Kao Race L. , Magovern George J. 
Published: September 2023

Six male mongrel dogs were studied on left ventricular bypass (left atrium to femoral artery) for twenty-four hours without anti-coagulation. The circuit consisted of standard perfusion cannulae, polyvinylchloride tubing, polycarbonate connectors, and the new Bio-Pump 80. Bypass flows averaged 2.2 1/m. Hematologic and biochemical parameters were measured according to protocol.
The coagulation profile during the 24 hours remained normal. The prothrombin time, partial thromboplastin time, and fibrinogen values were not statistically different from preoperative control values. Fibrin split products were consistently negative and hemoglobin, hematocrit, and platelets were stable over the 24 hour period. Serum hemoglobin levels were negligible over the course of the experiment. The biochemical results also remained at normal levels, with the exception of creatinine, which was significantly lower.
All dogs were electively sacrificed at the end of the 24 hour assist period. Autopsy revealed minor renal infarcts in two animals; all other organs were found to be grossly intact. There were no technical problems with the Bio-Pump 80. Thrombi were seen at approximately twenty per cent of the connector/tubing junctions. Four of the Bio-Pumps had no thrombus accumulation in any part of the pump, while two pumps had small amounts of thrombus present around the center shaft.
Technical Considerations for Transporting Patients, by Air Ambulance, with Intra-Aortic Balloon Pumps
Authors: Kramer Richard P. , Snow Norman J. 
Published: September 2023

An increasing demand for the conveyance of patients with acute cardiac decompensation to tertiary cardiovascular centers in our service area prompted investigation of a method for utilizing the intra-aortic balloon pump on helicopters and fixed wing aircraft of the Metro Life Flight system.
Mounting a DatascopeR System 84 transport balloon console onto an aluminum helicopter litter allowed convenient loading and cabin configuration. Carbon dioxide CO2 was the driving gas, and no recognizable altitude effects occurred. Reliance on on-board electrical power minimized CO2 usage and maintained adequate reserves for complementary ground transportation. Compressor start-up can create a power drain which trips inverter circuit breakers. This can be avoided by connecting the tubing from the compressor to the console after it is running. Lengthening of the pressure tubing to the slave chamber facilitated patient movement. Special attention to CO2 tank position and ground support preparation (personnel and equipment) have assured safe, expeditious transportation for eight patients with cardiogenic shock (seven) or refractory angina pectoris (one).
Systemische agrohomöopathische Intervention auf der Grundlage
der metabolischen Ähnlichkeit lebender Organismen
Authors: Lorenzo Francesco Di , Dinelli Giovanni 
Published: September 2023

ZusammenfassungModerne Landwirtschaft muss den sich ändernden gesellschaftlichen
Anforderungen in Bezug auf die Lebensmittelqualität und auf die
Umweltfragen, die in Verbindung mit der Primärproduktion stehen
(z. B. Biodiversität, Wasser- und Luftqualität sowie
Klimawandel), gerecht werden. In diesem Zusammenhang sind
Win-win-Lösungen auf Betriebsebene erforderlich. Dazu gehören
eine nachhaltigere Lebensmittelproduktion, eine Verringerung der Luft-, Wasser-
und Bodenverschmutzung sowie stärkere Bemühungen um Erhaltung
der Biodiversität und der natürlichen Ressourcen. Zur
Bewältigung dieser Herausforderungen wird derzeit eine neue Disziplin
entwickelt, die als „systemische Agrohomöopathie“
bezeichnet wird. Dieser Ansatz berücksichtigt Pflanzen und ihre
Interaktionen mit der Umgebung als ein einheitliches Agrarökosystem,
„Holon“ genannt. Eine der Grundlagen dieses Ansatzes sind extrem
verdünnte Substanzen, deren Gebrauch für Landwirte unbedenklich
ist und die frei von ökologischen Nebenwirkungen sind. Dieser Bericht
beschreibt die Prinzipien und die Anwendung dieses Ansatzes.
Effekt der Behandlung mit isopathischem Arsenicum album C6 auf das
Wachstum von kontaminierten Weizensetzlingen
Authors: Bhikha Reyna 
Published: September 2023

ZusammenfassungDie Agrohomöopathie hat viele Vorteile für das Pflanzenwachstum,
wie z. B. die nichttoxische Eradikation von biotischem und abiotischem
Stress bei Pflanzen, sodass Pflanzen resistent gegenüber
Schädlingen und schädlichen Nebenwirkungen von Chemikalien
werden. Es gab Untersuchungen zur isopathischen Behandlung mit dem Mittel
Arsenicum album bei Weizensamen, die mit dem auch in Pestiziden vorkommenden
As₂O₃ kontaminiert waren. In einem einzelnen verblindeten, placebokontrollierten
Laborexperiment wurden die Auswirkungen einer isopathischen Behandlung mit
Arsenicum album C6 auf das Wachstum von Weizensetzlingen untersucht. Diese
Studie wurde sowohl quantitativ als auch qualitativ analysiert. Trotz der
positiven qualitativen Befunde ist die praktische Anwendbarkeit dieser Studie
begrenzt, da die quantitativen Befunde eine geringe bis mittlere
Effektgröße aufweisen.
The search for linguistically coherent accents
Authors: Cole Amanda , Strycharczuk Patrycja 
Published: September 2023

Abstract
Linguistic research refers to many related accents in Southeast England: Standard Southern British English (SSBE), Received Pronunciation (RP), Estuary English (EE), Cockney and Multicultural London English (MLE). However, there is inconsistency and imprecision in the demarcation of these accents based on linguistic and social factors. This paper delineates accents in Southeast England based on patterns of linguistic co-variation which we then relate to social predictors. We applied functional Principal Component Analysis to F1 and F2 measurements for diphthongs extracted from wordlist and passage productions for 193 young, south-eastern speakers. Principal Components were entered into a clustering analysis that identified patterns of linguistic co-occurrence. Three clusters emerge, broadly aligning with SSBE, MLE and EE for both linguistic and social factors. We illustrate the linguistic centre of gravity of the three diphthong systems for use as reference points in future research, and we discuss the need to make explicit how accents are defined.
CLIL teacher beliefs as they emerge working in tandem
Authors: Alas Ene , Ljalikova Aleksandra , Jung Merle 
Published: September 2023

Abstract
The current article investigates the beliefs of Content and Language Integrated Learning (CLIL) subject and language
teacher tandems in a situation where they worked in close contact to design and deliver a CLIL course. The aim was to discover their
underlying beliefs concerning setting learning goals, developing academic language proficiency, using authentic materials and cooperative
tasks, and managing assessment. The Interpretative Phenomenological Approach revealed both overlapping and idiosyncratic beliefs involving
all of the focal aspects. Common beliefs included the dominance of subject learning goals over language goals, the need to develop academic
language proficiency, the use of authentic materials and cooperative tasks as sources of subject knowledge and skills, as well as the need
to involve appropriate assessment in the process. Differences included flexibility in the process of goal setting, the definition of
academic language proficiency, the meaning of authentic learning materials and the repertoire of tools available for scaffolding learning
and managing assessment.