bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of the Society for Coronary Angiography and Interventions' lesion classification system in 14,133 patients with percutaneous coronary interventions in the current stent era
Authors: Krone Ronald J. , Kimmel Stephen E. , Laskey Warren K. , Klein Lloyd W. , Schechtman Kenneth B. , Cosentino J.J. Adolfo , Babb Joseph D. , Weiner Bonnie H.
Published: August 2002

We recently showed that the ACC/AHA coronary lesion classification could be simplified with no loss of predictive value (SCAI I = patent/non‐C; SCAI II = patent/C; SCAI III = occluded/non‐C; SCAI IV = occluded/C). We now test this system in a database reflecting current stent usage. Data from 14,133 patients with single‐native‐vessel interventions recorded in the Society for Coronary Angiography and Interventions (SCAI) Registry from July 1996 to July 1999 were analyzed. Stents were used in 60.2% of procedures. Logistic models predicting angiographic success suggested a slight, clinically insignificant preference for the SCAI classification (c‐statistic = 0.692 vs. 0.670). Models using clinical variables to predict major complications were superior to models using only lesion classification. Lesion characteristics were related to outcomes primarily in elective (not acute myocardial infarction) patients. In the current PCI device era, the simpler SCAI classification using 7 variables predicted interventional success and complications as well as or better than the ACC/AHA system requiring 26. Cathet Cardiovasc Intervent 2002;55:1–7. © 2002 Wiley‐Liss, Inc.
Initial experience and safety in the treatment of chronic total occlusions with fiberoptic guidance technology: Optical coherent reflectometry
Authors: Cordero Herbert , Warburton Katherine D. , Underwood Paul L. , Heuser Richard R.
Published: August 2002

Percutaneous treatment of chronic total coronary occlusions has been limited by procedural complications such as vessel injury or perforation. Optimizing visualization in the vessel with optical coherent reflectometry and a forward‐looking fiberoptic guidance technology may improve the safety and efficacy of percutaneous treatment of these lesions. Cathet Cardiovasc Intervent 2001;54:180–187. © 2001 Wiley‐Liss, Inc.
Reliability of fractional flow reserve measurements in patients with associated microvascular dysfunction: Importance of flow on translesional pressure gradient
Authors: Claeys Marc J. , Bosmans Johan M. , Hendrix Johan , Vrints Chris J.
Published: August 2002

Fractional flow reserve (FFR) has been applied with success as a lesion‐specific functional indicator of stenosis severity, at least in patients with normal microcirculation. This study sought to assess the reliability of FFR calculations in patients with associated microvascular dysfunction (e.g., post myocardial infarction, or post‐MI). First, the effect of coronary flow changes on translesional pressure gradient was assessed. Therefore, intracoronary pressure and flow was recorded simultaneously across 19 non–infarct‐related lesions (both pre‐ and postinterventional lesions with a mean diameter stenosis of 47% ± 12%). Measurements were performed by means of a pressure and Doppler wire during maximal hyperemia and also during submaximal hyperemia induced by low‐dose adenosine. The drop of coronary flow from 48 ± 23 ml/min during maximal hyperemia to 36 ± 18 ml/min during submaximal hyperemia was associated with a small decrease in translesional pressure gradient (from 22 ± 12 mm Hg to 19 ± 12 mm Hg; P = 0.02) and a small increase in the mean distal/arterial pressure ratio (Pd/Pa) going from 77% ± 11% to 81% ± 11% (P = 0.003). Then, intracoronary pressure and flow measurements were compared across 21 non–infarct‐related lesions vs. 22 matched infarct‐related lesions. For a similar angiographic stenosis severity (% DS = ± 44%), maximal flow was 48 ± 22 ml/min in the non‐infarct arteries and 37 ± 26 ml/min in the infarct arteries (P = 0.03), confirming the presence of severe microvascular dysfunction in infarct regions. Similar to the earlier findings, this hyperemic flow reduction in MI patients was associated with a small increase of FFR (= Pd/Pa): 79% ± 12% in no MI vs. 83% ± 12% in MI patients (P = 0.3). A reduction of hyperemic flow by + 5%, such as can be found in patients with severely impaired microvascular function, has a limited effect on FFR calculations (+ 5%). This finding allows the application of standard FFR calculations in a more general population of ischemic heart disease, including patients with recent MI. Cathet Cardiovasc Intervent 2001;54:427–434. © 2001 Wiley‐Liss, Inc.
Immunosuppressive effects of extracellular adenosine on immune cells: Implications for the pathogenesis of ADA SCID and immunomodulation
Authors: Gomez Gregorio , Apasov Sergey , Sitkovsky Michail V.
Published: August 2002

Signaling through extracellular adenosine receptors is believed to account for the wide‐ranging effects of adenosine. Interest of immunologists in adenosine stems from the observation that ADA deficiency leads to the inheritable SCID syndrome, and the data reviewed here indicate that at least some of the characteristics of ADA‐SCID may be a consequence of extracellular adenosine signaling. Studies of adenosine receptor and ADA‐deficient mice may provide the genetic evidence necessary to implicate extracellular adenosine as an important mediator in pathogenesis of ADA SCID and in demonstration of selectivity of adenosine‐based immunomodulating drugs. Drug Dev. Res. 53:218–224, 2001. Published 2001 Wiley‐Liss, Inc.
The role of increased liver triglyceride content: a culprit of diabetic hyperglycaemia?
Authors: Song Shaoming
Published: August 2002

The role of fat in the aetiology of insulin resistance and type 2 diabetes has been re‐considered in the present review. This is because of the questions raised by recent created mouse models imitating human lipodystrophy diabetes. It appears that hepatic steatosis, which is shared by both lipodystrophy and most if not all obesity patients, may play a key role in the pathogenesis of insulin resistance and type 2 diabetes despite the fact that lipodystrophy is an extreme state and occurs more rarely than obesity. The possible link between lipid and glucose metabolisms via peroxisome activity has been examined and its role in determining hyperglycaemia is suggested. Moreover, new avenues towards a better understanding of insulin resistance at the genomic level have also been proposed. It appears that one of the most fundamental biological phenomena, fuel selection, may underlie the causes of diabetic hyperglycaemia and perplex the role of fat in the aetiology of insulin resistance. Copyright © 2002 John Wiley & Sons, Ltd.
Quality statistics in canonical correspondence analysis
Authors: Graffelman Jan
Published: August 2002

Canonical correspondence analysis is an important multivariate tool in ecology. A key aspect of the analysis is the representation of species optima, where these optima are estimated by the weighted averages of the species with respect to environmental variables. This article shows that, strictly speaking, canonical correspondence analysis does not optimize the representation of the species optima but the inertia of the abundance matrix under linear constraints. It is argued that the eigenvalues obtained in the analysis, usually reported in applied studies, are a measure of the quality of the display of the abundance matrix, and only indicate the quality of representation of the species optima when environmental variables are uncorrelated. In practice, environmental variables are often correlated. Thus, additional quality statistics are needed to express how well the species optima are represented. In this article we derive quality statistics for the representation of the species optima and the environmental variables, and use artificial and empirical data to illustrate their use. Copyright © 2001 John Wiley & Sons, Ltd.
LPL polymorphism predicts stroke risk in men
Authors: Morrison Alanna C. , Ballantyne Christie M. , Bray Molly , Chambless Lloyd E. , Sharrett A. Richey , Boerwinkle Eric
Published: August 2002

Variation in lipid levels has been associated with atherosclerotic vascular disease, including stroke. Genes contributing to interindividual variation in lipid levels may play a role in the etiology of stroke, either through their effects on lipid synthesis and metabolism or through separate pathways. For this reason, we sought to examine the association between polymorphisms in the lipoprotein lipase (LPL) and apolipoprotein E (APOE) genes and subclinical and clinical stroke in the Atherosclerosis Risk in Communities (ARIC) Study. Subclinical stroke was determined by cerebral magnetic resonance imaging (MRI). Subclinical cerebral infarct cases (n = 197) were compared to a stratified random sample identified from individuals participating in the MRI examination (n = 200). Incidence of clinical ischemic stroke was determined by following the ARIC cohort for an average of 7.5 years for potential cerebrovascular events; 218 validated clinical ischemic strokes were identified. A stratified random sample of the ARIC cohort (CRS, n = 964) was used as the comparison group for clinical cases. The LPL S291‐carrying genotypes and APOE ϵ2‐ and ϵ4‐carrying genotypes were not significantly associated with subclinical or clinical stroke. The LPL X447‐containing genotypes were significantly associated with subclinical (odds ratio [OR], 4.32; 95% confidence interval [CI], 1.23–15.15; P = 0.020) and clinical stroke (hazard rate ratio [HRR], 2.57; 95% CI, 1.24–5.34; P = 0.01) in men, both by themselves and after adjustment for multiple stroke risk factors. The LPL S447X polymorphism is significantly associated with subclinical cerebral infarction and incident clinical ischemic stroke in men from a middle‐aged American population. This association does not appear to be mediated by triglyceride, high‐density lipoprotein (HDL)‐ and low‐density lipoprotein (LDL)‐cholesterol levels, or additional stroke risk factors. Genet. Epidemiol. 22:233–242, 2002. © 2002 Wiley‐Liss, Inc.
Completeness and accuracy of registration of ovarian cancer in the cancer registry of Norway
Authors: Tingulstad Solveig , Halvorsen Tore , Norstein Jarle , Hagen Bjørn , Skjeldestad Finn Egil
Published: August 2002

Completeness of reporting and accuracy of the diagnosis of ovarian cancer from one health region in Norway to the Cancer Registry were examined. Data kept by the Cancer Registry were evaluated against discharge diagnosis data from all 8 hospitals in the health region during the period of 1987–1996. The assessment of the accuracy of the diagnosis recorded in the Cancer Registry was based on review of all medical records in the hospital setting and on slide review of all histologic diagnoses. The overall completeness of reporting ovarian cancer to the Cancer Registry was 99.6%. The organ specific completeness of registration of histologic verified ovarian cancer within the Cancer Registry was 95.3%; 0.9% was erroneously coded and 3.5% had their diagnosis changed to ovarian cancer at re‐evaluation. Of all ovarian cancer cases registered at the Cancer Registry, 91% had a primary histologic diagnosis. Among 591 cases identified with a histologic diagnosis in the Cancer Registry, the accuracy of the diagnosis was estimated at 92%. Coding errors were found in 2% of these cases, while in 6% of the cases it was not possible to reproduce the original diagnosis of ovarian cancer at re‐evaluation. In order to provide data of high quality for cancer surveillance a cancer registry needs several data providers, such as histopathologic laboratory reports and clinical reports. In addition, assessment of reported data through stringent quality assurance procedures within the registry are necessary for reaching a nearly 100% completeness of registration as found for ovarian cancer in the Cancer Registry of Norway. © 2002 Wiley‐Liss, Inc.
Heat shock mediated modulation of protein kinase CK2 in the nuclear matrix*
Authors: Davis Alan T. , Wang Huamin , Zhang Ping , Ahmed Khalil
Published: August 2002

Nuclear matrix, a key structure in the nuclear framework, appears to be a particularly responsive target during heat shock treatment of cells. We have previously shown that nuclear matrix is a preferential target for protein kinase CK2 signaling in the nucleus. The levels of CK2 in the nuclear matrix undergo dynamic changes in response to altered growth status in the cell. Here, we have demonstrated that CK2 targeting to the nuclear matrix is profoundly influenced by treatment of the cells to temperatures higher than 37°C. Rapid increase in the nuclear matrix association of CK2 is observed when cells are placed at temperatures of 41 and 45°C. This effect at 45°C was higher than at 41°C, and was time‐dependent. Also, different cell lines behaved in a qualitatively similar manner though the quantitative responses differed. The modulations in the nuclear matrix associated CK2 in response to heat shock appear to be due to trafficking of the enzyme between cytosolic and nuclear compartments. In addition, it was noted that isolated nuclei subjected to heat shock also responded by a shuttling of the intrinsic CK2 to the nuclear matrix compartment. These results suggest that modulations in CK2 in the nuclear compartment in response to the heat stress occur not only by a translocation of the enzyme from the cytoplasmic compartment to the nuclear compartment, but also that there is a redistribution of the kinase within the nuclear compartment resulting in a preferential association with the nuclear matrix. The results support the notion that CK2 association with the nuclear matrix in response to heat shock may serve a protective role in the cell response to stress. J. Cell. Biochem. 85: 583–591, 2002. Published 2002 Wiley‐Liss, Inc.
A case illustration of resistance from a gestalt‐experiential perspective
Authors: Engle David , Holiman Marjorie
Published: August 2002

The case of Victoria illustrates psychotherapy with a woman faced with a difficult and unexpected divorce. The authors present a summary of typical struggles faced by Victoria through three phases of therapy. The therapy focused initially on coping with the divorce, then moved to work on her career dissatisfaction, and finally to her efforts to develop a new relationship. The case presentation illustrates resistance as it manifested itself in both a behavioral manner and as in‐session resistance to awareness of internal states. The behavioral mode of resistance is manifested by her inability to follow through on decisions made in therapy sessions and by her interruptions of ongoing therapy. A transcript of a typical in‐session exchange illustrates the resistance to awareness. The authors also describe interventions intended to work with the resistance. © 2002 John Wiley & Sons, Inc. J Clin Psychol/In Session 58: 151–156, 2002.
Precision of magnetic resonance velocity and acceleration measurements: Theoretical issues and phantom experiments
Authors: Durand Emmanuel P. , Jolivet Odile , Itti Emmanuel , Tasu Jean‐Pierre , Bittoun Jacques
Published: August 2002

Magnetic resonance (MR) sequences have been developed for acquiring multiple components of velocity and/or acceleration in a reasonable time and with a single acquisition. They have many parameters that influence the precision of measurements: NS, the number of flow‐encoding steps; NEX, the number of signal accumulations; and ND, the number of dimensions. Our aims were to establish a general relationship revealing the precision of these measurements as a function of NS, ND, and NEX and to validate it by experiments using phantoms. Previous work on precision has been restricted to two‐step (NS = 2) or 1D (ND = 1) MR velocity measurements. We describe a comprehensive approach that encompasses both multistep and multidimensional strategies. Our theoretical formula gives the precision of velocity and acceleration measurements. It was validated experimentally with measurements on a rotating disk phantom. This phantom was much easier to handle than fluid‐based phantoms. It could be used to assess both velocity and acceleration sequences and provided accurate and precise assessments over a wide, adjustable range of values within a single experiment. Increasing each of the three parameters, NS, ND, and NEX, improves the precision but makes the acquisition time longer. However, if only one parameter is to be assessed, maximizing the number of steps (NS) is the most efficient way of improving the precision of measurements; if several parameters are of interest, they should be measured simultaneously. By contrast, increasing the number of signals accumulated (NEX) is the least efficient strategy. J. Magn. Reson. Imaging 2001;13:445–451. © 2001 Wiley‐Liss, Inc.
Nitric oxide and Coxsackievirus B3 myocarditis: Differential expression of inducible nitric oxide synthase in mouse heart after infection with virulent or attenuated virus
Authors: Bevan Adrian L. , Zhang Hongyi , Li Yanwen , Archard Leonard C.
Published: August 2002

Increased expression of inducible nitric oxide synthase (iNOS) has been found in inflammatory myocardial disease and increased production of nitric oxide (NO) has both an inhibitory effect on virus replication and a cytotoxic effect on host cells. To investigate the relationship between severity of enteroviral myocarditis and iNOS expression, a characterised murine model was infected with either cardiovirulent or an attenuated Coxsackievirus B3 and myocardial samples were collected on Day 7. The ability of these viruses to induce NOS expression was compared by measurement of iNOS enzyme activity and localisation of iNOS protein or peroxynitrite, a product of excessive NO production. In accordance with previous reports, high expression of iNOS was detected in mice infected with the cardiovirulent virus. The iNOS protein was located mainly in infiltrating macrophages in and around foci of necrotic myofibres where viral genomic RNA was detected. In contrast, the level of iNOS expression was significantly lower in mice infected with the attenuated virus. This correlates with fewer and smaller myocarditic lesions and less infiltrating cells in the heart. iNOS was not detected in mock‐infected mice by the above assays. These findings suggest that one mechanism of attenuation may be associated with the reduced ability of the variant to induce NOS expression in the heart. This also confirms a cytotoxic role for NO in the pathogenesis of Coxsackievirus B3‐induced myocarditis. J. Med. Virol. 64:175–182, 2001. © 2001 Wiley‐Liss, Inc.
Single molecule surface‐enhanced resonance Raman scattering on colloidal silver and Langmuir–Blodgett monolayers coated with silver overlayers
Authors: Lemma Tibebe , Aroca Ricardo F.
Published: August 2002

Single molecule detection (SMD) of a new perylene dye containing a terminal NH2 group, n‐butylimidoethylenamineperylene (PTCD‐NH2), adsorbed on colloidal silver and silver island films was achieved using surface‐enhanced resonance Raman scattering (SERRS). This work represents the first comparative SERRS study where SMD was achieved using two of the most commonly used SERS substrates, colloidal silver and silver island films. SERRS spectra were obtained in colloidal silver solution with analyte concentrations varying from 10−6 to 10−12 M and also from silver sols dispersed and dried on polysilane‐coated substrates. SERRS on silver islands was obtained by vacuum evaporation of a 6 nm mass thickness silver overlayer on to a Langmuir–Blodgett (LB) monolayer containing 1, 10 and 100 dye molecules per µm2 of surface area. The LB technique is ideally suited to obtain spatially resolved spectra of single molecules dispersed in the matrix of a fatty acid, as is used here to obtain SERRS from a few dye molecules found within the area of illumination. The characteristic fundamental vibrational wavenumbers observed in the single molecule SERRS spectra were unequivocally assigned with the help of their first overtones and combinations. Copyright © 2002 John Wiley & Sons, Ltd.
The effect of irrigation on peak temperatures in nerve root, dura, and intervertebral disc during laser‐assisted foraminoplasty
Authors: Hafez M.I. , Zhou S. , Coombs R.R.H , McCarthy I.D.
Published: August 2002

Background and Objective

The Holmium: YAG (Ho: YAG) laser has been used for the ablation of prolapsed discs but alternative techniques are available, and this application remains controversial. It also has potential for the decompression of nerve roots within narrowed foraminae with the technique of endoscopic laser foraminoplasty. Traditional methods of decompression necessitate a major surgical procedure with potential destabilisation of the lumbar spinal segment. Nevertheless, minimally invasive techniques are attractive only if serious complications can be avoided. This study reports the peak temperatures reached in surrounding tissues with and without saline irrigation.

Study Design/Materials and Methods

Investigation of the hypothesis was carried out in excised sheep lumbar spines. T‐type thermocouples were used for the measurement of tissue temperatures during laser ablation of nerve root foraminae. The temperature was assessed in the nerve root, dura mater, and disc space.

Results

The Ho: YAG laser was effective in widening the foraminae by approximately 1.5 mm with a total energy of 4.60 kJ. This was statistically significant in both vertical and horizontal directions (P < 0.0003 and P < 0.00005, respectively). The mean temperature of the nerve root, dura, and disc space during the procedure was 44 ± 3.1°C, 42.8 ± 4.7°C, and 41 ± 3.4°C respectively. There were transient high peaks seen in the temperature profiles. Using saline irrigation at 27 ml/minutes these temperatures were reduced to 34.1 ± 1.8°C (P = 0.0002), 34.9 ± 1.5°C (P = 0.002), and 37.2 ± 1.2°C (P < 0.014), for nerve roots, dura, and disc space respectively.

Conclusions

Laser ablation of bone and ligament for nerve root decompression using the Ho: YAG laser may offer substantial advantages, but the risk of serious complication may only be avoided if the technique is combined with saline irrigation. Lasers Surg. Med. 29:33–37, 2001. © 2001 Wiley‐Liss, Inc.
Nonlinearity suppression of electroabsorption modulator through dual‐parallel modulation
Authors: Jung Hyun‐Do , Lee Gyu‐Woong , Han Sang‐Kook , Choi Woo‐Young
Published: August 2002

A novel linearization method is proposed to increase the dynamic range of an electro‐absorption modulator in suboctave bandwidth operation by exploiting the fact that the phase of third‐order intermodulation distortion varies with the dc bias voltage. A reduction of 14 dB in IMD3 and a subsequent increase of the linear dynamic range were experimentally obtained. © 2001 John Wiley & Sons, Inc. Microwave Opt Technol Lett 29: 2–5, 2001.
Application of generalized differential quadrature rule in Blasius and Onsager equations
Authors: Liu G. R. , Wu T. Y.
Published: August 2002

The generalized differential quadrature rule (GDQR) proposed recently by the authors is applied here to third‐order non‐linear differential equations of the Blasius type and to sixth‐order linear Onsager differential equations. High (⩾3rd)‐order differential equations in fluid mechanics are dealt with without using δ‐point techniques. The half‐space domain is simplified in a practical way. Accurate results are obtained for both kinds of problems. The wide applicability of the GDQR in high‐order differential equations is manifested further through this work. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis of new poly(amide imide)s with (n‐alkyloxy)phenyloxy side branches
Authors: Choi Kyung Ho , Lee Kyung Hoon , Jung Jin Chul
Published: August 2002

Two series of new poly(amide imide)s having (n‐alkyoxy)phenyloxy side branches with various lengths, poly{p‐phenyleneiminoterephthaloylimino‐p‐phenylene[3,6‐di(n‐alkyloxy)phenyloxy]pyromellitimide}s (PCmTAs, m = 4, 8, 12) and poly{p‐phenyleneiminosebacoylimino‐p‐phenylene[3,6‐di(n‐alkyloxy)‐phenyloxy]‐ pyromellitimide}s (PCmSeAs, m = 4, 8, 12), were prepared by condensation of terephthalamide‐N,N′‐4,4′‐dianiline (TA) and sebacamide‐N,N′‐4,4′‐dianiline (SeA) with 3,6‐di[4‐(n‐alkyloxy)phenyloxy]pyromellitic dianhydrides, respectively. The inherent viscosities of the polymers were in the 0.82–1.20 dL/g range. The polymers were highly soluble in N‐methylpyrolidinone (NMP), even at room temperature and soluble in other polar aprotic solvents on heating. The PCmTAs, which have aromatic backbones, were thermally more stable (431–442 °C) than the PCmSeAs, which have an octamethylene unit in the main chain (407–409 °C). Degradation of weight up to 900 °C corresponded with the loss of side chain contents. The PCmTAs exhibited no phase transition, whereas two endothermic peaks were observed for each of the PCmSeAs. Wide‐angle X‐ray diffractometer investigations revealed that both polymers are amorphous and the n‐alkyloxy side chains are present in a layered structure. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3818–3825, 2001
Structure of ionic aggregates of ionomers. II. Effect of humidity and temperature on ethylene and styrene ionomers
Authors: Tsujita Y. , Yasuda M. , Kinoshita T. , Takizawa A. , Yoshimizu H. , Davies G. R.
Published: August 2002

Small‐angle X‐ray scattering profiles of ethylene and styrene ionomers were studied to clarify the structure of ionic aggregates as a function of humidity or temperature. The intensity and position of ionic cluster peaks were observed for ionomers with a certain degree of neutralization. The intensity of the ionic cluster peak for the ethylene ionomer increased with increasing relative humidity, but it decreased for the styrene ionomer. With increasing humidity, the position of the ionic cluster peak shifted to smaller angles for both ionomers. The size of the ionic aggregates and the closest approach distance between the aggregates were analyzed, and the results varied with humidity for both ionomers. The size did not vary markedly with a change in temperature, whereas the closest approach distance and number of ionic aggregates changed slightly with the melting temperature of the ethylene ionomer and the glass‐transition temperature of the styrene ionomer. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 831–839, 2002
Improving hydrogen isotope ratio measurements for on‐line chromium reduction systems
Authors: Nelson Stephen T. , Dettman David
Published: August 2002

Recent advances in on‐line metal [U, Mn, Cr] reduction systems for the automated analysis of δDVSMOW in water and organic solvents greatly increases sample throughput. However, several sources of uncertainty are inherent in these systems, including analytical reproducibility, fractionation of reference gas in the inlet system, and memory effects, as well as error introduced during data normalization that must be quantified. A careful consideration of these sources of uncertainty suggests that accuracy to <1‰ may be difficult to achieve due to the combined effects of analytical error and uncertainty in the calibration of secondary laboratory standards. However, for internally consistent data sets, it may be possible to measure relative differences between samples at the ∼0.5‰ level or below. In addition to describing methods for data reduction, strategies for minimizing and managing uncertainty are presented along with a recipe for greatly increasing reactor life in Cr‐reduction systems. Increased reactor life reduces consumable costs by a factor of 10. Copyright © 2001 John Wiley & Sons, Ltd.
Analysis of petrol and diesel vapour and vehicle engine exhaust gases using selected ion flow tube mass spectrometry
Authors: Smith David , Cheng Ping , Španěl Patrik
Published: August 2002

We have used selected ion flow tube mass spectrometry (SIFT‐MS) to analyse the vapours emitted by petrol and diesel fuels and the exhaust gases from petrol (spark ignition) and diesel (compression ignition) engine vehicles fitted with catalytic converters. Only those components of these media that have significant vapour pressures at ambient temperatures were analysed and thus particulates were obviously not detected. These media have been analysed using the full scope of SIFT‐MS, i.e., with the three available precursor ions H3O+, NO+ and O2+. The combination of the H3O+ and NO+ analyses is seen to be essential to distinguish between different product ions at the same mass‐to‐charge ratio (m/z) especially in identifying aldehydes in the exhaust gases. The O2+ precursor ions are used to detect and quantify the large amount of nitric oxide present in the exhaust gases from both engine types. The petrol and diesel vapours consist almost exclusively of aliphatic alkanes, alkenes and alkynes (and dienes) and aromatic hydrocarbons. Some of these compounds appear in the exhaust gases together with several aldehydes, viz. formaldehyde, acetaldehyde, pentanal, pentenal (acrolein), butenal, and also methanol and ethanol. Acetone, nitric oxide and ammonia are also present, acetone and nitric oxide being much more abundant in the diesel exhaust gas than in the petrol exhaust gas. These data were obtained from samples collected into pre‐evacuated stainless steel vessels. Trapping of the volatile compounds from the gas samples is not required and analysis was completed a few minutes later. All the above compounds are detected simultaneously, which demonstrates the value of SIFT‐MS in this area of research. Copyright © 2002 John Wiley & Sons, Ltd.
Kinematics of a six‐dof fixation device for long‐bone fracture reduction
Authors: Gregorio Raffaele Di , Parenti‐Castelli Vincenzo
Published: August 2002

This paper presents a kinematic model for the control of a six‐degrees‐of‐freedom
(dof) mechanism proposed for long‐bone fracture reduction. The mechanism is an evolution of
previous mechanisms known as Ilizarov‐like fixation devices. These previous mechanisms perform the
fracture reduction by following a trial‐and‐error adjustment procedure that subjects the patient to
several x‐ray exposures and provides only an approximate positioning of the two segments of the broken
bone to be reduced; in fact, the adjustment procedure relies upon a three‐dof instead of the
six‐dof mechanism that would be necessary for the correct reciprocal location of the bone segments. This
procedure also makes the success of the reduction highly dependent on the surgeon's skill. This paper
exploits the hardware of a previous device and transforms it into a six‐dof mechanism. A kinematic model
of the six‐dof mechanism is presented. The model provides the adjustment parameters that enable the
correct mutual location of the two segments of the broken bone. Consequently, the procedure is freed from the
trial‐and‐error modality, and the correct reduction is less dependent on the surgeon's skill.
© 2001 John Wiley & Sons, Inc.
Minimal residual disease in thyroid carcinoma
Authors: Weber Theresia , Klar Ernst
Published: August 2002

The detection of disseminated tumor cells in differentiated (DTC) and medullary thyroid carcinomas (MTC) is one of the main topics in current thyroid cancer research. Immunocytochemistry and polymerase chain reaction (PCR) provide the tools for the identification of a small number of thyroid cancer cells in peripheral blood and cervical lymph nodes. Thyroid‐specific markers, such as thyroglobulin (Tg) mRNA and thyroid peroxidase (TPO) mRNA, have been detected with RT‐PCR in blood samples of tumor patients and healthy control subjects. To prevent false‐positive results, quantitative PCR systems were established. Tumor‐specific markers, such as telomerase activity and cytokeratin 20 (CK20), have been detected in various epithelial tumors. Amplification products of these markers were found in blood samples and in fine‐needle aspiration (FNA) biopsies of patients with thyroid carcinomas. Using molecular detection of disseminated tumor cells in cervical lymph nodes with CK20 RT‐PCR, a higher percentage of involved lymph nodes was detected compared to immunohistochemistry. The results of the presented studies may help researchers to develop more sensitive methods for early tumor cell dissemination, and refine risk groups that might benefit from more extensive surgical procedures or adjuvant therapy. However, the prognostic value of minimal residual disease (MRD) in thyroid carcinoma has to be confirmed in large or multicenter prospective studies. Semin. Surg. Oncol. 20:272–277, 2001. © 2001 Wiley‐Liss, Inc.
Parameter refinement in the analysis of X‐ray irradiated samples
Authors: Carreras A. , Bonetto R. , Stutz G. , Trincavelli J. , Castellano G.
Published: August 2002

Although the refinement of parameters is a well known method in the scope of X‐ray diffraction, it also appears as a powerful tool in other spectroscopic techniques. This work presents a method for the refinement of different atomic and experimental parameters in X‐ray fluorescence (XRF). It consists of minimizing the differences between an experimental X‐ray spectrum and a function proposed to account for the characteristic peaks and background spectrum from the corresponding sample, as well as for detection artifacts. The algorithm starts from some initial values for the different parameters involved, and a numerical iterative procedure produces improved values for them. After the general aspects of the method for refining XRF parameters are presented, a simple application is given for spectra measured in metallic samples with a monochromatic beam from a synchrotron source. In this case, the optimization algorithm is used for the determination of relative transition probabilities for the K shell. Copyright © 2002 John Wiley & Sons, Ltd.
Acute hypoxia and cytochrome P450–mediated hepatic drug metabolism in humans
Authors: Jürgens Gesche , Christensen Hanne Rolighed , Brøsen Kim , Sonne Jesper , Loft Steffen , Olsen Niels Vidiendal
Published: August 2002

Objective

Our objective was to investigate the effect of acute hypoxia on the activity of hepatic cytochrome P450 (CYP) enzymes.

Methods

Twelve healthy subjects who lived at sea level were exposed to altitude‐induced hypoxia for 7 days at 4559 m above sea level. Hepatic CYP enzyme activity was measured before departure, at 24 and 96 hours after arrival to high‐altitude location, and at 1 month after return to sea level. CYP enzyme activities were measured by means of the metabolic ratios of sparteine (CYP2D6), endogenous cortisol metabolism (CYP3A4), and caffeine (CYP1A2), as well as by the S/R ratio of mephenytoin (CYP2C19) and antipyrine clearance.

Results

The metabolic ratio of sparteine increased after 24 hours at high altitude (median difference, 0.15; 95% confidence interval, 0.05 to 0.28) and remained increased after 96 hours. The ratio decreased after return to sea level (median difference, −0.15; 95% confidence interval, −0.29 to −0.03; P = .016, Friedman test). The metabolic ratio of cortisol decreased after 24 hours (median difference, −2.0; 95% confidence interval, −3.5 to −0.5) but returned to sea level values after 96 hours at high altitude (median difference, 1.6; 95% confidence interval, 1.0 to 4.2; P = .047, Friedman test). These changes indicate a small decrease in the activity of CYP2D6 and CYP3A4. There were no significant changes regarding the metabolic ratio of caffeine, the S/R ratio of mephenytoin, or antipyrine clearance.

Conclusion

The small changes observed suggest that acute hypoxia has no clinically significant effects on CYP enzymes in humans.

Clinical Pharmacology & Therapeutics (2002) 71, 214–220; doi: 10.1067/mcp.2002.121789
Setting Intentions
Authors: Venkataraman Vinayak
Published: January 2024

In this narrative medicine essay, an oncologist ruminates over a chemotherapy consent form about the goals of therapy for a young adult whose body is filled with an aggressive cancer most commonly seen in children.
Is Vaccination Approaching a Dangerous Tipping Point?
Authors: Marks Peter , Califf Robert
Published: January 2024

This Viewpoint discusses declining vaccination rates in the US, specifically against COVID-19, and the ways in which clinicians and the Food and Drug Administration can counter the current large volume of vaccine misinformation.
Trends in High-Acuity Cardiovascular Events During the COVID-19 Pandemic
Authors: Wharam J. Franklin , LeCates Robert F. , Thomas Ann , Zhang Fang , Argetsinger Stephanie , Garabedian Laura F. , Galbraith Alison A.
Published: January 2024

This cohort study describes changes in myocardial infarction and stroke hospitalizations as well as congestive heart failure, angina, and transient ischemic attack incidents months before and after March 2020 among insured people in New England.
Evaluation of Changes in Prices and Purchases Following Implementation of Sugar-Sweetened Beverage Taxes Across the US
Authors: Kaplan Scott , White Justin S. , Madsen Kristine A. , Basu Sanjay , Villas-Boas Sofia B. , Schillinger Dean
Published: January 2024

Importance

Sugar-sweetened beverage (SSB) taxes are promoted as key policies to reduce cardiometabolic diseases and other conditions, but comprehensive analyses of SSB taxes in the US have been difficult because of the absence of sufficiently large data samples and methods limitations.

Objective

To estimate changes in SSB prices and purchases following SSB taxes in 5 large US cities.

Design, Setting, and Participants

In this cross-sectional study with an augmented synthetic control analysis, changes in prices and purchases of SSBs were estimated following SSB tax implementation in Boulder, Colorado; Philadelphia, Pennsylvania; Oakland, California; Seattle, Washington; and San Francisco, California. Changes in SSB prices (in US dollars) and purchases (volume in ounces) in these cities in the 2 years following tax implementation were estimated and compared with control groups constructed from other cities. Changes in adjacent, untaxed areas were assessed to detect any increase in cross-border purchases. Data used for this analysis spanned from January 1, 2012, to February 29, 2020, and were analyzed between June 1, 2022, and September 29, 2023.

Main Outcomes and Measures

The main outcomes were the changes in SSB prices and volume purchased.

Results

Using nutritional information, 5500 unique universal product codes were classified as SSBs, according to tax designations. The sample included 26 338 stores—496 located in treated localities, 1340 in bordering localities, and 24 502 in the donor pool. Prices of SSBs increased by an average of 33.1% (95% CI, 14.0% to 52.2%; P < .001) during the 2 years following tax implementation, corresponding to an average price increase of 1.3¢ per oz and a 92% tax pass-through rate from distributors to consumers. SSB purchases declined in total volume by an average of 33.0% (95% CI, −2.2% to −63.8%; P = .04) following tax implementation, corresponding to a −1.00 price elasticity of demand. The observed price increase and corresponding volume decrease immediately followed tax implementation, and both outcomes were sustained in the months thereafter. No evidence of increased cross-border purchases following tax implementation was found.

Conclusions and Relevance

In this cross-sectional study, SSB taxes led to substantial, consistent declines in SSB purchases across 5 taxed cities following price increases associated with those taxes. Scaling SSB taxes nationally could yield substantial public health benefits.
Maternal Diabetes and Overweight and Congenital Heart Defects in Offspring
Authors: Turunen Riitta , Pulakka Anna , Metsälä Johanna , Vahlberg Tero , Ojala Tiina , Gissler Mika , Kajantie Eero , Helle Emmi
Published: January 2024

Importance

Maternal diabetes and overweight or obesity are known to be associated with increased risk of congenital heart defects (CHDs) in offspring, but there are no large studies analyzing outcomes associated with these factors in 1 model.

Objective

To investigate the association of maternal diabetes and overweight or obesity with CHDs among offspring in 1 model.

Design, Setting, and Participants

This nationwide, population-based register study was conducted in a birth cohort from Finland consisting of all children born between 2006 and 2016 (620 751 individuals) and their mothers. Data were analyzed from January 2022 until November 2023.

Exposures

Maternal prepregnancy body mass index (BMI; calculated as weight in kilograms divided by height in meters squared), categorized as underweight (<18.5), normal (18.5-24.9), overweight (25.0-29.9), and obesity (≥30), was assessed. Maternal diabetes status, classified as no diabetes, type 1 diabetes (T1D), type 2 or other diabetes, and gestational diabetes, was assessed.

Main Outcomes and Measures

Odds ratios (ORs) of isolated CHDs in children were found. In addition, 9 anatomical CHD subgroups were studied.

Results

Of 620 751 children (316 802 males [51.0%]; 573 259 mothers aged 20-40 years [92.3%]) born in Finland during the study period, 10 254 children (1.7%) had an isolated CHD. Maternal T1D was associated with increased odds of having a child with any CHD (OR, 3.77 [95% CI, 3.26-4.36]) and 6 of 9 CHD subgroups (OR range, 3.28 [95% CI, 1.55-6.95] for other septal defects to 7.39 [95% CI, 3.00-18.21] for transposition of great arteries) compared with no maternal diabetes. Maternal overweight was associated with left ventricular outflow tract obstruction (OR, 1.28 [95% CI, 1.10-1.49]) and ventricular septal defects (OR, 0.92 [95% CI, 0.86-0.98]), and obesity was associated with complex defects (OR, 2.70 [95% CI, 1.14-6.43]) and right outflow tract obstruction (OR, 1.31 [95% CI, 1.09-1.58]) compared with normal maternal BMI.

Conclusions and Relevance

This study found that maternal T1D was associated with increased risk for most types of CHD in offspring, while obesity and overweight were associated with increased risk for complex defects and outflow tract obstruction and decreased risk for ventricular septal defects. These different risk profiles of T1D and overweight and obesity may suggest distinct underlying teratogenic mechanisms.
In Operando Near‐Field Optical Investigation of Memristive Ta2O5 Thin Film Devices with a Graphene Top Electrode
Authors: Wirth Konstantin G. , Goss Kalle , Heisig Thomas , Bauerschmidt Christoph , Hessler Andreas , Li Haolong , Waldecker Lutz , Dittmann Regina , Taubner Thomas
Published: January 2024

Resistive switching devices based on metal oxides are candidates for nonvolatile memory storage. They often rely on the valence change mechanism, the field‐induced movement of donor ions leading to nanoscale conductive paths in filamentary‐type devices. Devices usually consist of a transition metal oxide like Ta2O5 sandwiched between two metal electrodes. Critical parameters of the devices, such as cycle‐to‐cycle variability, Roff/Ron ratio, and endurance depend on the morphology and composition of the filaments. However, investigating filaments on the nanoscale is cumbersome, and commonly applied techniques such as conductive atomic force or transmission electron microscopy require delaminating the metal top electrode, inhibiting in operando investigations over many switching cycles. Here, the authors use infrared scattering‐type scanning near‐field optical microscopy (s‐SNOM) to investigate resistive switching in Ta2O5 films with a graphene top electrode in operando and reveal individual filaments on the device level. By selecting an appropriate illumination frequency, the authors can trace the evolution of filaments and the joule heating‐induced retraction of the top electrode until device failure. s‐SNOM promises a deeper understanding of resistive switching devices’ microscopic switching behavior and applies to a wide range of resistive switching oxides, such as HfO2, SrTiO3, and SiO2.
Novel‐Ink‐Based Direct Ink Writing of Ti6Al4V Scaffolds with Sub‐300 µm Structural Pores for Superior Cell Proliferation and Differentiation
Authors: Xu Chao , Xu Yan , Chen Hao , Han Qing , Wu Wenzheng , Zhang Lu , Liu Qingping , Wang Jincheng , Ren Luquan
Published: January 2024

Ti6Al4V scaffolds with pore sizes between 300 and 600 µm are deemed suitable for bone tissue engineering. However, a significant proportion of human bone pores are smaller than 300 µm, playing a crucial role in cell proliferation, differentiation, and bone regeneration. Ti6Al4V scaffolds with these small‐sized pores are not successfully fabricated, and their cytocompatibility remains unknown. The study presents a novel ink formula specifically tailored for fabricating Ti6Al4V scaffolds featuring precise and unobstructed sub‐300 µm structural pores, achieved by investigating the rheological properties and printability of five inks containing 60–77.5 vol% Ti6Al4V powders and bisolvent binders. Ti6Al4V scaffolds with 50–600 µm pores are fabricated via direct ink writing and subjected to in vitro assays with MC3T3‐E1 and bone marrow mesenchymal stem cells. The 100 µm pore‐sized scaffolds exhibit the highest cell adhesion and proliferation capacity based on live/dead assay, FITC‐phalloidin/4',6‐diamidino‐2‐phenylindole staining, and cell count kit 8 assay. The alizarin red staining, real‐time quantitative PCR assay, and immunocytochemical staining demonstrate the superior osteogenic differentiation potential of 100 and 200 µm pore‐sized scaffolds. The importance of sub‐300 µm structrual pores is highlighted, redefining the optimal pore size for Ti6Al4V scaffolds and advancing bone tissue engineering and clinical medicine development.
Spectral Engineering of Optical Microresonators in Anisotropic Lithium Niobate Crystal
Authors: Zhang Ke , Chen Yikun , Sun Wenzhao , Chen Zhaoxi , Feng Hanke , Wang Cheng
Published: January 2024

On‐chip optical microresonators are essential building blocks in integrated optics. The ability to arbitrarily engineer their resonant frequencies is crucial for exploring novel physics in synthetic frequency dimensions and practical applications like nonlinear optical parametric processes and dispersion‐engineered frequency comb generation. Photonic crystal ring (PhCR) resonators are a versatile tool for such arbitrary frequency engineering, by controllably creating mode splitting at selected resonances. To date, these PhCRs have mostly been demonstrated in isotropic photonic materials, while such engineering can be significantly more complicated in anisotropic platforms that often offer more fruitful optical properties. Here, the spectral engineering of chip‐scale optical microresonators is realized in the anisotropic lithium niobate (LN) crystal by a gradient design that precisely compensates for variations in both refractive index and perturbation strength. Controllable frequency splitting is experimentally demonstrated at single and multiple selected resonances in LN PhCR resonators with different sizes, while maintaining high quality‐factors up to 1 × 106. Moreover, a sharp boundary is experimentally constructed in the synthetic frequency dimension based on an actively modulated x‐cut LN gradient‐PhCR, opening up new paths toward the arbitrary control of electro‐optic comb spectral shapes and exploration of novel physics in the frequency degree of freedom.