bluuebunny/crossref_metadata_2025_split huggingface dataset:
Grain Size of Quartz as an Indicator of Winter Monsoon Strength on the Loess Plateau of Central China during the Last 130,000 Yr
Authors: Xiao Jule , Porter Stephen C. , An Zhisheng , Kumai Hisao , Yoshikawa Shusaku 
Published: October 2002

AbstractThe Chinese loess-paleosol sequence constitutes an important record of variations in Asian monsoon climate over the past 2.4 myr. Magnetic susceptibility of loess and paleosols has been used as a proxy for summer monsoon intensity, while median grain size has been regarded as a measure of the strength of winter monsoon winds that were responsible for most of the dust transport. However, median grain size is only an approximate index of winter monsoon strength because both paleosols and loess have been modified, to various degrees, by weathering processes that have produced pedogenic clay. The quartz component of loess and paleosols is largely unaffected by weathering processes and therefore constitutes a more reliable proxy index of monsoon wind strength. Median grain size (Qmd) and maximum grain size (Qmax) values of monomineralic quartz isolated from the loess-paleosol section at Luochuan in the central Loess Plateau are characterized by two main intervals during the last ca. 130,000 yr when these parameters were significantly greater than 9 and 85 μm, respectively, and three main intervals when they were lower. The data imply that the winter monsoon weakened during the intervals with low Qmd and Qmax values, which coincide with marine oxygen isotope stages 5, 3, and 1, and was strongest ca. 67,000 and 20,000 yr ago during isotope stages 4 and 2. However, both quartz grainsize records display second-order high-frequency, high-amplitude variations, which are lacking in the magnetic susceptibility record, that imply rapid and significant changes in atmospheric conditions that affect dust transport and deposition.
The Eem Stable Isotope Record along the GRIP Ice Core and Its Interpretation
Authors: Johnsen Sigfus J. , Clausen Henrik B. , Dansgaard Willi , Gundestrup Niels S. , Hammer Claus U. , Tauber Henrik 
Published: October 2002

AbstractA 3029-m-long deep ice core extending nearly to bedrock has been drilled at the very top of the Greenland ice sheet (Summit) by the Greenland Ice-core Project (GRIP), an international European joint effort organized by the European Science Foundation. The ice core reaches back to 250,000 yr B.P. according to dating based partly on stratigraphic methods and partly on ice-flow modeling. A continuous and detailed stable isotope (δ18O) profile along the entire core depicts dramatic temperature changes in Greenland through the last two glacial cycles, including abrupt climatic shifts during the Eem/Sangamon Interglaciation, which is elsewhere recorded as a warm and stable period. The stratigraphic continuity of the Eemian layers has therefore been scrutinized. New ice core studies, comprising cloudy band observations, deconvolution, and frequency analyses, lead to the conclusion that the climate instability suggested during the Eem Interglaciation in Greenland is likely to be real, though no conclusive evidence is available. Whereas latitudinal displacements of the North Atlantic Ocean current are considered the immediate cause of the glacial climate instability, longitudinal displacements may be the immediate cause of the Eemian instability. If so, the Eemian climate changes will be much subdued outside the Arctic region and will probably only be recognizable in sedimentary sequences of high sensitivity and temporal resolution.
U-Series Dating by the TIMS Technique of Land Snails from Paleosols in the Canary Islands
Authors: Hillaire-Marcel Claude , Ghaleb Bassam , Gariépy Clément , Zazo Cari , Hoyos Manolo , Goy Jose-Luis 
Published: October 2002

AbstractA sequence of seven superimposed paleosols developed on eolian calcarenites and alluvium was sampled on the island of Lanzarote in order to examine the possibility of dating land snail shells by the U-series method, using a TIMS technique allowing measurement of U and Th isotopes in very small samples. In the lower six units, the fossil shells yielded D-allo/L-isoleucine (A/I) ratios of about 0.5 and apparent AMS 14C ages ranging from 41,000 to 34,000 yr B.P., indicating that most paleosols formed during a relatively short mid-Würm humid episode. The upper unit (paleosol 7) yielded more variable A/I ratios (ranging from 0.6 to 0.2) and a younger 14C age ∼27,000 yr B.P. Most samples contained enough U to allow the calculation of U-series ages, after correction for the presence of a detrital component. In samples containing a few tens of ppb of U (paleosols 1, 2, 3, 6, and 7), the ages are strongly dependent upon the model used for the correction. In samples containing more than 300 ppb of U (paleosols 4 and 5), concordant ages of ∼31,000 ± 1000 yr were obtained regardless of the correction model used. U uptake in these shells occurred during one single early diagenetic phase, soon after burial, since shells of modern snails do not contain any significant amount of U. The arid conditions subsequent to the mid-Würm humid episode have likely ensured since then a fair closure of the radioactive system.
Age of Sheep Creek Tephra (Pleistocene) in Central Alaska from Thermoluminescence Dating of Bracketing Loess
Authors: Berger Glenn W. , Péwé Troy L. , Westgate John A. , Preece Shari J. 
Published: October 2002

AbstractThe age of the Sheep Creek tephra (SCt), a widespread marker ash bed in eastern Alaska and western Yukon Territory, has been ambiguous and controversial. We have obtained three reliable thermoluminescence age estimates from bracketing loess near Fairbanks that imply a deposition age of about 190,000 ± 20,000 yr for SCt. Three of six loess samples near and closely bracketing the SCt beds near Fairbanks yielded younger age estimates (∼117,000 and ∼135,000 yr), most likely (based on field aspects) because of reworking and contamination by translocated grains. The new, reliable age assignment of 190,000 yr confirms independent stratigraphic evidence of a pre-last interglaciation age, and stratigraphic evidence from one site (Upper Eva Creek) that SCt is older than the more-widespread 140,000-yr-old Old Crow tephra. The SCt age also has implications for regional correlations of glacial and nonglacial deposits. In particular, it supports the stratigraphic and geomorphic interpretation that the Delta Glaciation in the east-central Alaska Range and the Reid Glaciation in western Yukon Territory are older than the last interglaciation (isotope substage 5e).
Late Quaternary Glaciation and Postglacial Stratigraphy of the Northern Pacific Margin of Canada
Authors: Barrie J. Vaughn , Conway Kim W. 
Published: October 2002

AbstractAreas of southeastern Alaska and the Queen Charlotte Islands of the northwestern Pacific coast of North America were considered to be ice free during the late Wisconsinan glaciation and glacial refugia existed. However, a glacier extended from mainland North America to the shelfbreak in Dixon Entrance separating Alaska and the Queen Charlotte Islands. Glacial retreat to the east began sometime after 15,000 to 16,00014C yr B.P. and ice had completely left Dixon Entrance by 13,500 to 13,00014C yr B.P. A rapid sea-level regression occurred soon after deglaciation began, due to isostatic rebound, with relative sea level falling to approximately 150 m below present in central Dixon Entrance, decreasing the size of the inlet by about 30 percent by 12,40014C yr B.P. The late Quaternary glacial and postglacial stratigraphic sequence is more than 100 m thick overlying older Pleistocene sediments and Tertiary bedrock. A late Wisconsinan diamicton is overlain by glaciomarine muds formed between approximately 14,400 and 13,00014C yr B.P. Contemporaneous with the deposition of the glaciomarine muds an extensive outwash deposit formed off the northern coast of the Queen Charlotte Islands to a present depth of 150 m. During the sea-level lowstand and subsequent transgression, a reworked sand unit was deposited over much of the seafloor to depths greater than 450 m. The unit is exposed at the seafloor over much of the region, suggesting that seabed hydrodynamic energy levels were high after 13,00014C yr B.P. and remain so today.
Variation of Rb/Sr Ratios in the Loess-Paleosol Sequences of Central China during the Last 130,000 Years and Their Implications for Monsoon Paleoclimatology
Authors: Chen Jun , An Zhisheng , Head John 
Published: October 2002

AbstractRb, Sr, and magnetic susceptibility have been measured in the last interglacial–glacial loess profiles at Luochuan and Huanxian, central China. A high degree of similarity between the parameters in both profiles suggests that variations of Rb/Sr ratios in the sequence can be regarded as an indicator of East Asian summer monsoon strength. Matching the Rb/Sr record with the SPECMAP δ18O curve suggests that the Rb/Sr ratio responds sensitively to changes of the East Asian monsoon induced by global ice-volume variation.
A First Step to Reconciling the GRIP and GISP2 Ice-Core Chronologies, 0–14,500 yr B.P.
Authors: Southon John 
Published: October 2002

Abstractδ18O records from the GISP2 and GRIP ice cores are widely used as benchmark paleoclimate chronologies, but there are significant differences between the two time scales. The present study shows that offsets between the two chronologies over the past 14,500 yr do not accumulate gradually, but appear over two short intervals of 100–200 yr. An initial offset of 80 yr occurs close to 3300–3400 yr B.P., and another 100 yr of slip appears at the start of the Younger Dryas. Since these discrepancies are localized, resolving them may be far easier than if large sections of both cores required reexamination.
Primary hyperparathyroidism: Renal calcium excretion in patients with and without renal stone disease before and after parathyroidectomy
Authors: Frøkjaer Vibe G. , Mollerup Charlotte L. 
Published: October 2002

AbstractThe effect of parathyroidectomy on renal calcium excretion per 24 hours in patients with primary hyperparathyroidism with and without a history of renal stone disease was evaluated. Altogether, 91 patients operated on for primary hyperparathyroidism formed the study group for preoperative analysis. Of these patients, 42 were evaluated 1 to 3 years postoperatively. The median preoperative serum calcium level was 2.92 mmol/L, and it was the same for patients with or without renal stones. Preoperatively we found no differences in renal calcium excretion between patients with and without renal stone disease. The median renal calcium excretion was 6.80 mmol/24 hr. At 1 to 3 years after successful parathyroidectomy the group with renal stone disease had higher renal calcium excretion than the group without renal stones (p=0.03). The reduced effect of parathyroidectomy on renal calcium excretion in the patients with renal stone disease indicates that factors not related to the hyper‐parathyroid state could contribute to disturbances in renal calcium excretion and hence stone formation. In conclusion, the pathologic basis for renal stone formation in patients with primary hyperparathyroidism might not be the hyperparathyroid state alone; stone formation could be related to other predisposing factors as well. Therefore, although parathyroidectomy can cure hyperparathyroidism, the curative effect on renal stone disease should be reconsidered.
Long‐term survival of patients with stage IV hypopharyngeal cancer: Impact of fundus rotation gastroplasty
Authors: Schilling Martin K. , Eichenberger Martin , Maurer Christoph A. , Greiner Richard , Zbären Peter , Büchler Markus W. 
Published: October 2002

AbstractStage IV circular hypopharyngeal cancer is a disease with poor long‐term survival, and the only means of cure—surgery—is associated with high morbidity. All patients admitted with circular hypopharyngeal cancer and extension to the esophagus were enrolled in a multidisciplinary treatment protocol, including circular laryngopharyngoesophagectomy with tracheostomy, neck dissection, and pull‐up of a fundus rotation gastric tube that was anastomosed to the oropharynx. Five weeks postoperatively high‐dose radiotherapy (60 Gy) was given to the cervical region. Altogether, 18 qualifying patients were explored cervically, were found to have resectable lesions (i.e., without carotid artery infiltration), and were included in the protocol. After laryngopharyngoesophagectomy, an elongated gastric tube was pulled up to the oropharynx. The average distance bridged with the tube was 32±4 cm. No anastomotic leaks were found on postoperative Gastrografin swallow, and oral feeding was started between days 5 and 8. Patients were discharged with normal oral feeding on day 21 (±17 days). Diarrhea, postprandial fullness, and reflux resolved within 6 months postoperatively. Five patients died during the follow‐up period of 42 months (range 3–63 months): three due to cardiac events 18 and 38 months postoperatively and two within 12 months with residual disease and tumor recurrence, respectively. The estimated 5‐year survival was 60%. We concluded that an aggressive multidisciplinary approach including circular laryngopharyngoesophagectomy, neck dissection, and high‐dose radiotherapy ascertains good long‐term survival and good functional results in patients with advanced hypopharyngeal cancer when the intestinal continuity is reconstructed with a fundus rotation gastroplasty.
Comparison of vital dye‐guided lymphatic mapping and dye plus gamma probe‐guided sentinel node biopsy in breast cancer
Authors: Cserni Gábor , Rajtár Mária , Boross Gábor , Sinkó Mária , Svébis Mihály , Baitás Béla 
Published: October 2002

AbstractThe optimal technique for sentinel lymph node biopsy (SLNB) is still debated. SLNB with peritumoral injection of Patent blue dye was performed in 129 clinically T1‐T2 and NO breast cancers in 127 patients (group A); it was later replaced by combined dye and radiocolloid‐guided SLNB preceded by lymphoscintigraphy in 72 breast cancer patients (group B). This study compares these two methods. All patients underwent completion axillary dissection. Means of 1.4 and 1.3 SLNs were identified in groups A and B, respectively. The mean number of non‐SLNs for the whole series was 14.9 (range 5–42). The first 53 cases of lymphatic mapping (dye only) comprised the institutional learning period during which the identification rate of at least 1 SLN in 30 consecutive attempts reached 90%. The identification rate for the subsequent 76 group A patients was 92%. The accuracy rate of SLNBs for overall axillary nodal status prediction and the false‐negative rate for group A patients (after excluding the learning‐phase cases) were 93% and 10%, respectively. All 72 group B cases had at least one SLN identified, and only one false‐negative case occurred in this group (accuracy and false‐negative rates of 99% and 3%, respectively). Both the dye‐only and the combined SLNB methods are suitable for SLN identification, but the latter works better and results in higher accuracy, a higher negative predictive value, and a lower false‐negative rate. It is therefore the method of choice.
Granulocyte elastase release and pulmonary hemodynamics in patients with mitral valvular disease
Authors: Gohra Hidenori , Mikamo Akihito , Okada Haruhiko , Hamano Kimikazu , Zempo Nobuya , Esato Kensuke 
Published: October 2002

AbstractIn patients with atrial septal defect in whom pulmonary hypertension could develop as a consequence of left‐to‐right shunt, the extent of neutrophil‐mediated lung injury induced by cardiopulmonary bypass (CPB) is related to the degree of increase in the preoperative pulmonary artery pressure. In the present study, we investigated the relationship between levels of granulocyte elastase (GEL) after CPB and preoperative pulmonary hemodynamics or changes in pulmonary function after the operation in patients with mitral valve disease, in whom pulmonary hypertension could develop as a result of pulmonary venous congestion. The plasma levels of GEL were measured before and after CPB in patients who underwent mitral valve replacement. Respiratory index (RI) was evaluated preoperatively and postoperatively. Preoperative pulmonary hemodynamics were determined within one month of the operation. Granulocyte elastase level rose significantly after CPB from baseline (134.3±44.6 mg/L versus 2042.1±1215.0 mg/L; p<0.001). Peak level of GEL was significantly correlated with preoperative systolic pulmonary artery pressure (r=0.71; p=0.020), mean pulmonary artery pressure (r=0.64;p=0.046), pulmonary capillary wedge pressure (r=0.68; p=0.032), and pulmonary‐to‐systemic arterial pressure ratio (r=0.64; p= 0.045), but not with the hemodynamic variables for pulmonary blood flow or pulmonary resistance. Moreover, the value of (Postoperative RI — Preoperative RI)/Preoperative RI was positively correlated with the peak level of GEL (r=0.76; p=0.011). In conclusion, in patients with mitral valvular disease, as in those with atrial septal defect, the increase in GEL level after CPB is proportional to the increase in preoperative pulmonary artery pressure, which may cause the accordant pulmonary vascular damage.
Risk indicators for varicose veins in forty‐ to sixty‐year‐olds in the tampere varicose vein study
Authors: Laurikka Jari O. , Sisto Tero , Tarkka Matti R. , Auvinen Ossi , Hakama Matti 
Published: October 2002

AbstractThe objectives of the study were to discover the main determinants for the prevalence of varicose veins in a general population, and to assess the possibilities for prevention of this common surgical disease. Varicose veins were evaluated in three defined cohorts of 3284 men and 3590 women aged 40, 50, and 60 years by using a validated questionnaire. The response rate was 75% among men and 86% among women, and varicose veins were determined by self‐assessment. Increasing age, female sex, childbirths, standing posture at work, higher weight or height, and positive family history were significantly associated with varicose veins in a univariate analysis. These factors were further taken into a multivariate logistic regression analysis, and female gender (adjusted odds ratio, OR 2.2), increasing age (OR 2.2–2.8), a reported positive family history for varicose veins (OR 4.9), increasing number of births (OR 1.2–2.8), standing posture at work (OR 1.6), and higher weight (OR 1.2) and height (OR 1.4) were found to independent and significant risk indicators of varicose veins. Increasing age, positive family history of varicose veins, and child‐births in women were the most important factors in terms of population etiologic fractions. Familial predisposition and pregnancy‐related factors bear important associations with varicose veins. Thus prevention of varicose veins appears to be difficult. Varicose veins are nonlethal and, therefore, higher age is related to higher prevalence.
Changes in serum hyaluronic acid levels and expression of CD44 and CD44 mRNA in hepatic sinusoidal endothelial cells after major hepatectomy in cirrhotic rats
Authors: Saegusa Shotaro , Isaji Shuji , Kawarada Yoshifumi 
Published: October 2002

AbstractSerum hyaluronic acid (HA) is widely distributed in connective tissues, and the majority of circulating HA is degraded by hepatic sinusoidal endothelial cells (SECs) via a receptor recycling pathway. Our previous clinical study revealed that monitoring serum HA levels after hepatectomy is useful in predicting the development of liver failure. In the present study, to determine the mechanism of the high HA levels after hepatectomy, especially in patients with liver cirrhosis, expression of the major HA receptor, CD44, and its mRNA was investigated in SECs isolated from rats with thioacetamide‐induced liver cirrhosis subjected to 70% hepatectomy (group I) and from rats with a normal liver that were subjected to 70% hepatectomy (group II). The 48‐hour postoperative survival rate in group I (13.3%) was significantly lower than in group II (100%). In group II, the expression of CD44 mRNA had increased significantly at 6 hours after hepatectomy, and this was followed by progressive increases in expression of CD44, indicating activation of SEC function. The increased serum HA levels after hepatectomy in group II became normal as CD44 expression increased. By contrast, the expression of CD44 and CD44 mRNA in group I was markedly attenuated after hepatectomy. The very low CD44 expression was followed by a significant and sustained increase in serum HA levels, indicating functional failure of the SECs. These results suggest that the significantly impaired functional reserve of SECs in liver cirrhosis is associated with increased mortality after 70% hepatectomy.
Changes in the response of neutrophils to endotoxin priming following major abdominal surgery
Authors: Moriwaki Yoshihiro , Sugiyama Mitsugi , Ozawa Yukihiro , Mochizuki Yasuhisa , Kunisaki Chikara , Kamiya Noriyuki , Yamazaki Yasunobu , Suda Takashi 
Published: October 2002

AbstractEndotoxin (ETX) primes polymorphonuclear cells (PMNs) for the subsequent release of reactive oxygen species (ROS) in response to various stimulants such as phorbol myristate acetate (PMA). Although PMNs contribute to oxidative stress after stimulation by standard stimulants and after priming by many humoral factors, it is unknown whether the PMNs from patients at different postoperative times exhibit the same response to the same standard stimulant. We examined the response of PMA—induced production of ROS from PMNs at various intervals after major abdominal surgery in response to ETX priming. This study was a prospective clinical and laboratory study conducted over a 7‐day period that involved 25 patients who were referred for elective major abdominal surgery (8 for gastric cancer, 9 for colonic cancer, 8 for rectal cancer). Blood was sampled on the day before operation and on postoperative days (PODs) 1, 3, and 7. For each sample we measured luminol‐dependent chemiluminescence (CL), the time to peak counts (Tmax) of PMNs stimulated by PMA, and the serum ETX level. We studied the correlation between CL and ETX in samples from PODs 1 and 3. We also studied the CL of PMNs on PODs 1 and 3 preincubated (primed) with various concentrations of ETX (0, 20, 40, 60, and 100 pg/ml). We found that CL decreased on POD 1 compared with the preoperative level (p<0.05) because of the decreased Tmax. The level of CL per 1 µl of whole blood, however, was higher on PODs 1 and 3 than preoperatively. During this time, leukocytosis should compensate for the impaired production of ROS by an individual PMN. The serum ETX level was increased on POD 1 (p<0.05). There was a negative correlation between CL and ETX on POD 1 (correlation coefficient −0.62, p<0.01) and a positive correlation on POD 3 (0.61, p<0.01). CL on POD 3 was accelerated by ETX priming, but the CL on POD 1 was depressed by the priming using a low concentration of ETX. The mode of the response of PMNs to ETX priming differed between PODs 1 and 3. On POD 1 the responses of PMNs to environmental stimulants is suppressed, but by POD 3 these responses had increased.