Fullerene size controls the selective complexation of [11]CPP with pristine and endohedral fullerenes.

The ability of the carbon nanoring [11]cycloparaphenylene ([11]CPP) for coordinating fullerenes has been tested using a series of hosts, including the pristine fullerenes C60, C70, C76 and C78, the clusterfullerene Sc3N@C80, monometallic endofullerenes Y@C82 and Tm@C82, and dimetallic endofullerenes Y2@C82 and Lu2@C82. A systematic theoretical study employing dispersion corrected density functional methods has been carried out in order to explore the characteristics of the complexes and the strength of the interaction. Depending on the dimer, complexation energies span from around -36 kcal mol-1 with C60 to -53 kcal mol-1 with the C82 derivatives. Dispersion is the main stabilizing contribution in these dimers, so the molecules arrange to maximize the number of close interatomic contacts. Since most fullerenes can properly fill the cavity of the nanoring the stability of the complexes is pretty similar, with the exception of the smallest fullerenes. The complexes with endohedral fullerenes show similar stabilities in all cases studied, with no noticeable dependence on the nature of the endohedral species. The results obtained suggest that fullerenes larger than C76 could be selectively encapsulated by [11]CPP compared to smaller fullerenes.

A theoretical study of complexes between fullerenes and concave receptors with interest in photovoltaics.

The complexation of the pristine fullerenes C60 and C70 and the endohedral fullerenes Sc3N@C80 and Sc3N@C68 has been tested using a series of hosts of different nature, including the buckybowls corannulene and sumanene, a zinc porphyrin, a chloro boron subphthalocyanine, and a corannulene pentasubstituted with nitrile groups. A systematic theoretical study has been carried out in order to explore both the strength of the interaction and the feasibility for electron transfer of the dimers. Dispersion is the main stabilizing contribution in these dimers, so both molecules orientate so as to maximize the number of close contacts among atoms. As a consequence, all host molecules interact with C70 by the long axis. C60 and Sc3N@C80 are more spherically shaped, so there is no clear preference for the position of the host molecule, though endohedral fullerenes are encapsulated preferentially by the face without contacts with the inner cluster. Complexation energies increase with the contact surface between molecules in the complex. The most stable complexes with fullerenes are formed by the subphthalocyanine and the CN-pentasubstituted corannulene. Depending on the dimer, complexation energies span from around -15 kcal mol-1 of C60 with corannulene to -24 kcal mol-1 of Sc3N@C80 with the subphthalocyanine. Some of the dimers seem to be capable of acting as a donor-acceptor pair, leading to charge transfer states with a neat separation of charge, thus being candidates for organic photovoltaic devices. Endohedral fullerenes are less prone to these donor-acceptor transitions, with charge transfer taking place from the carbon cage to the endohedral cluster. cora5CN, with its inverted polarity, also shows charge transfer upon excitation but with the fullerene acting as a donor and the buckybowl as an acceptor.

Evolution of phospholipid contents during the production of quark cheese from buttermilk.

We report the evolution of phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylcholine (PC), phosphatidylserine (PS), and sphingomyelin (SM) contents during the production of quark cheese from buttermilk by successive ultrafiltration concentration, enrichment with cream, concurrent homogenization and pasteurization, fermentative coagulation, and separation of quark from whey by further ultrafiltration. Buttermilk is richer than milk itself in phospholipids that afford desirable functional and technological properties, and is widely used in dairy products. To investigate how phospholipid content is affected by end-product production processes such as ultrafiltration, homogenization, pasteurization or coagulation, we measured the phospholipids at several stages of each of 5 industrial-scale quark cheese production runs. In each run, 10,000L of buttermilk was concentrated to half volume by ultrafiltration, enriched with cream, homogenized, pasteurized, inoculated with lactic acid bacteria, incubated to coagulation, and once more concentrated to half volume by ultrafiltration. Phospholipid contents were determined by HPLC with evaporative light scattering detection in the starting buttermilk, concentrated buttermilk, ultrafiltrate, cream-enriched concentrated buttermilk (both before and after concurrent homogenization and pasteurization), coagulate, and quark, and also in the rinsings obtained when the ultrafiltration equipment was washed following initial concentration. The average phospholipid content of buttermilk was approximately 5 times that of milk, and the phospholipid content of buttermilk fat 26 to 29 times that of milk fat. Although phospholipids did not cross ultrafiltration membranes, significant losses occurred during ultrafiltration (due to retention on the membranes) and during the homogenization and pasteurization process. During coagulation, however, phospholipid content rose, presumably as a consequence of the proliferation of the inoculated lactic acid bacteria. In spite of these changes in total phospholipid content, the relative proportions of the phospholipids studied remain fairly stable throughout quark production (PE>PC>SM>PS>PI) and similar to those found in the milk of the region, except that SM content was lower than in milk.

Milk phospholipids: Organic milk and milk rich in conjugated linoleic acid compared with conventional milk.

The objective of this study was to compare the phospholipid content of conventional milk with that of organic milk and milk rich in conjugated linoleic acid (CLA). The membrane enclosing the fat globules of milk is composed, in part, of phospholipids, which have properties of interest for the development of so-called functional foods and technologically novel ingredients. They include phosphatidylethanolamine (PE), phosphatidylinositol (PI), phosphatidylcholine (PC), phosphatidylserine (PS), and the sphingophospholipid sphingomyelin (SM). Milk from organically managed cows contains higher levels of vitamins, antioxidants, and unsaturated fatty acids than conventionally produced milk, but we know of no study with analogous comparisons of major phospholipid contents. In addition, the use of polyunsaturated-lipid-rich feed supplement (extruded linseed) has been reported to increase the phospholipid content of milk. Because supplementation with linseed and increased unsaturated fatty acid content are the main dietary modifications used for production of CLA-rich milk, we investigated whether these modifications would lead to this milk having higher phospholipid content. We used HPLC with evaporative light scattering detection to determine PE, PI, PC, PS, and SM contents in 16 samples of organic milk and 8 samples of CLA-rich milk, in each case together with matching reference samples of conventionally produced milk taken on the same days and in the same geographical areas as the organic and CLA-rich samples. Compared with conventional milk and milk fat, organic milk and milk fat had significantly higher levels of all the phospholipids studied. This is attributable to the differences between the 2 systems of milk production, among which the most influential are probably differences in diet and physical exercise. The CLA-rich milk fat had significantly higher levels of PI, PS, and PC than conventional milk fat, which is also attributed to dietary differences: rations for CLA-rich milk production included linseed supplement and contained less maize meal than conventional rations and a greater proportion of unsaturated fatty acids and salts. The relative proportions of the phospholipids studied were similar in all 3 types of milk, descending in the order PE>(PC, SM)>PS>PI, with PC being slightly more abundant than SM in organic milk and vice versa in CLA-rich milk.

Application of ATP bioluminescence for evaluation of surface cleanliness of milking equipment.

The ATP bioluminescence method was used to evaluate the cleanliness of milking equipment surfaces (teat cup rubbers, teat dip containers, milk receivers, and pipeline joints) in dairy farms in Galicia (northwest Spain) with parlour, pipeline tie-stall or bucket tie-stall milking systems. The cleanest surfaces were teat cup rubbers. The use of non-chlorinated water for cleaning, and of pipeline or bucket tie-stall milking systems, was associated with high ATP bioluminescence values. However, ATP bioluminescence values only explained 12% of the variability in bulk-tank bacterial count; this is attributable to the importance of other factors (notably the correct functioning of the tank cooling system) for maintenance of low bacterial count.

Prevalence of and risk factors for Listeria species on dairy farms.

This cross-sectional study determined the prevalence of Listeria spp. in bulk-tank milk on dairy farms in the region of Galicia in northwest Spain. The aim was to identify management practices associated with the presence of Listeria spp. and possible effects on milk hygienic quality. A total of 98 farms was randomly selected on the basis of an expected prevalence of 6.5% for Listeria monocytogenes from 20,107 dairy farms in the region. Bulk-tank milk samples were obtained from 98 farms, fecal samples from lactating cows from 97 farms, and silage samples from 83 farms. Listeria monocytogenes was detected in 6.1, 9.3, and 6.0% of these samples, respectively. Statistical analyses confirmed the relationship between low silage quality (as indicated by high pH) and presence of Listeria spp. in silage (29.5 vs. 6.2% for pH above or below 4.5, respectively). Only milking system [tie-stall systems (28.6%) vs. parlor milking (10%)] and inadequately controlled milking order [yes (32.0%) vs. no (10.7%)] had statistically significant effects on management practices for increasing the risk of Listeria contamination of bulk-tank milk.

A comparative theoretical study of the pericyclic-pseudopericyclic character in a group of cyclizations of dienylketenes to cyclohexadienones.

A comprehensive B3LYP/6-31+G* study of the nature of 6pi electrocyclizations of four different dienylketenes (2-furanyl, 2-pyrrolyl, cyclopenta-1,3-dienyl, and 2-thiophenyl-substituted ketenes) to corresponding cyclohexadienones was carried out. An analogous system ((3Z)-4-(3H-pyrrol-2-yl)buta-1,3-dien-1-one) was also analyzed. For this purpose, the complete pathways were determined (reactants, products, transition states, and the IRC connecting reactants and products), and changes in different magnetic properties (magnetic susceptibility, chi, magnetic susceptibility anisotropy, chi anis, and the nucleus-independent chemical shifts, NICS) were monitored along the reaction profiles with a view to estimating the aromatization associated to the processes. We have also applied the ACID (anisotropy of the current-induced density) method with the same intention. The deep analysis of the results indicates a pericyclic character of the processes for the dienylketenes despite the relatively small NICS values in the transition states. Only the reaction of (3Z)-4-(3H-pyrrol-2-yl)buta-1,3-dien-1-one presents pseudopericyclic character due to the in-plane attack of the lone pair on nitrogen.

Mineral analysis in rabbit meat from Galicia (NW Spain).

A total of 54 rabbits 50, 70 and 90 days old, were taken from farms in Galicia (NW Spain); 18 rabbits of each age were sampled. The minerals in the muscle meat from the back legs of the rabbits were analysed, and the following average concentrations were found: ash 1.21/100g, potassium 388mg/100g; phosphorus 237mg/100g; sodium 60mg/100g; magnesium 27mg/100g; calcium 8.7mg/100g; zinc 10.9mg/kg; iron 5.56mg/kg; copper 0.78mg/kg; and manganese 0.33mg/kg. The high potassium and low sodium concentration may make rabbit meat particularly recommended for hypertension diets. Rabbit meat is rich in phosphorus, and 100g provides approximately 30% of the recommended daily intake. However, rabbit meat provides less zinc and iron than meats of other species. The Galician rabbit meat analysed in this study, shows higher copper and manganese, and lower calcium contents than those found in the literature for rabbit meat of other origins.

Determination of polarimetric parameters of honey by near-infrared transflectance spectroscopy.

NIR transflectance spectroscopy was used to determine polarimetric parameters (direct polarization, polarization after inversion, specific rotation in dry matter, and polarization due to nonmonosaccharides) and sucrose in honey. In total, 156 honey samples were collected during 1992 (45 samples), 1995 (56 samples), and 1996 (55 samples). Samples were analyzed by NIR spectroscopy and polarimetric methods. Calibration (118 samples) and validation (38 samples) sets were made up; honeys from the three years were included in both sets. Calibrations were performed by modified partial least-squares regression and scatter correction by standard normal variation and detrend methods. For direct polarization, polarization after inversion, specific rotation in dry matter, and polarization due to nonmonosaccharides, good statistics (bias, SEV, and R(2)) were obtained for the validation set, and no statistically (p = 0.05) significant differences were found between instrumental and polarimetric methods for these parameters. Statistical data for sucrose were not as good as those of the other parameters. Therefore, NIR spectroscopy is not an effective method for quantitative analysis of sucrose in these honey samples. However, NIR spectroscopy may be an acceptable method for semiquantitative evaluation of sucrose for honeys, such as those in our study, containing up to 3% of sucrose. Further work is necessary to validate the uncertainty at higher levels.

Semi-automated direct epifluorescent filter technique for total bacterial count in raw milk.

The Direct Epifluorescent Filter Technique (DEFT) and the reference method of counting total bacterial colonies on Petri dishes were compared. IDF Standards 128 (1985) and 161A (1995) were applied. A total of 496 samples of milk were analyzed. Colony forming units per microL milk were transformed to decimal logarithmic units: log (cfu/microL). The repeatability standard deviation, Sr = 0.114, was typical for a routine microbiological method. To study the carryover at different levels of bacteria, 3 tests were performed on milk samples of approximately 100, 700, and >1000 cfu/microL. For the first 2 experiments, no carryover was detected; in the milk sample with >1000 cfu/microL, the carryover was <0.12%. When the DEFT counts were regressed versus the reference method, the values of the slope and intercept were 0.92 and 0.17, respectively; the correlation coefficient was r = 0.84; and the residual standard deviation was Syx = 0.287. The paired t-test showed that the reference method and DEFT do not give significantly different results (p = 0.05).

Major components of honey analysis by near-infrared transflectance spectroscopy.

NIR transflectance spectroscopy was used to analyze fructose, glucose, and moisture in honey. A total of 161 honey samples were collected during 1992 (46), 1995 (58), and 1996 (57). Samples were analyzed by instrumental, enzymatic (fructose and glucose), and refractometric (moisture) methods. Initially, different calibrations were performed for each of the 3 years of sampling. Good predictions were obtained for all three components with equations of the particular year. But good predictions were not always obtained when the equations calculated one year were applied to samples from another year. To perform a lasting calibration, unique calibration (121 samples) and validation (40 samples) sets were built; honeys of the 3 years were included in both sets. Good statistics (bias, standard error of validation (SEV), and R(2)) were obtained for all three components of the validation set. No statistically significant differences (p = 0.05) were found between instrumental and reference methods.

Effects of Lactobacillus strains on the ripening and organoleptic characteristics of Arzúa-Ulloa cheese.

Seven batches of Arzúa-Ulloa, a short-ripened soft cow's milk cheese produced in Galicia (NW Spain), were prepared from pasteurized milk. Two control batches of cheese (CB) were made with an acid-aromatic starter containing Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. lactis var. diacetylactis, isolated from raw-milk Arzúa-Ulloa cheeses. Five batches of cheese (LB) were made with the acid-aromatic starter plus one of five strains of mesophilic homofermentative Lactobacillus spp.: four of them isolated from raw-milk Arzúa-Ulloa cheese (characterized in previous works) and the remaining was a commercial Lactobacillus strain. Higher counts of mesophilic viable bacteria, lactic acid bacteria and citrate-fermenting bacteria were found on days 1 or 15 of ripening, while higher counts of lactobacilli were found on day 30 of ripening. On day 1 of ripening the highest diacetyl-acetoin content was noted in the CB, but after day 15 the diacetyl-acetoin content was similar or higher in three of the five LB. The mean degradation of beta-casein in CB was higher than in LB, while the degradation of alpha(s1)-casein was higher in LB. The mean contents of nitrogen-soluble fractions were slightly higher in the LB than in the CB. Volatile free fatty acid (VFFA) contents were, in general, greater in LB than in CB and maximum amounts were determined on day 15 of maturation. Sensorial analysis indicated a more acid taste was in LB, while bitter and astringent tastes were more intense in CB. A positive correlation was found between beta-casein degradation and bitter taste. Yogurt and butter aromas were more intense in CB and in two of the five LB. Firmness was lower in LB and a negative correlation was found between this parameter and alpha(s1)-casein degradation. Crumbliness showed a positive correlation with beta-casein degradation. The use of the Lactobacillus strains assessed in this study is recommended for Arzúa-Ulloa cheese manufacture, in order to enhance the desirable characteristics of this cheese variety, i.e., a soft texture due to alpha(s1)-casein proteolysis but without the bitter taste due to beta-casein degradation and a spicy and slightly rancid aroma and taste.

Torquoselectivity in the cationic cyclopentannelation of (2Z)-hexa-2,4,5-trienal acetals.

Inter- and intramolecular trapping experiments and density functional theory ab initio calculations for model systems are consistent with the acid-catalyzed rearrangement of 2-[(1Z)-hexa-1,3,4-trienyl]dioxolanes 1 to tetrahydroalkylidenecyclopenta-1,4-dioxins 4; this involves the electrocyclic ring closure of substituted hydroxypentadienyl carbocations. The reaction, which may be considered a variant of the Nazarov cyclization, occurs much more readily than the standard Nazarov cyclization, proceeding rapidly even at -30 degrees C. B3LYP/6-31G**//HF/6-31G** calculations for models 36, 38 and 40 predict that the two alternative conrotations at the cyclization termini are associated with activation energies differing by 0.55, 0.56 and 1.60 kcalmol(-1), respectively, in favour of the R-outwards rotation. This last value corresponds to an E-41/Z-41 product ratio of >99:1 at -60 degrees C, in consonance with the experimental observation that divinylallene 1a rearranges exclusively to E-4a at temperatures below -30 degrees C. At higher temperatures the torquoselectivity of the reaction 1a-->4a is masked by subsequent isomerization to the Z isomer, the greater stability of which is attributable to steric interaction between the substituent at the exocyclic double bond and the bulky neighbouring tBu group in the E isomer.

Effects of the addition of Enterococcus faecalis in Cebreiro cheese manufacture.

Ten batches of Cebreiro, a fresh or short-ripened acid-curd cheese, produced in the Galician mountains (NW Spain) were prepared from pasteurized milk inoculated with microorganisms isolated from raw-milk cheese. Two control batches were made with a Lactococcus lactis subsp. lactis starter; 8 batches were made with the lactococcal starter plus one of eight Enterococcus faecalis cultures: 4 E. faecalis var. liquefaciens (EFLB) and 4 E. faecalis var. faecalis (EFFB). Whey dry matter in the EFLB was notably higher than in the control batches and this was related to lower cheese yields. After over 15 days storage the highest counts of both aerobic bacteria and lactic acid bacteria were observed for the EFLB. The lower content in protein on dry matter was found in the EFLB. The beta-casein broke down to a greater extent in the EFLB than in the EFFB, the lowest values being obtained for the control batches. The higher level of hydrolysis of alphax1-casein and maximum peptide alpha(s1) - I/alpha(s1)-casein ratio were obtained for EFFB at day 15 of storage. In all the batches made with enterococci soluble nitrogen was higher than in the control batches, with the highest values in the EFLB. In all the batches made with enterococci, volatile free fatty acid, long-chain free fatty acids and diacetyl and acetoin contents at days 10 and 15 of storage were higher than in the control batches, the highest values being obtained for EFLB. Acetic acid in all batches accounted for the main proportion of the volatile free fatty acids. Butyric and caproic acids were not detected in the volatile free fatty acids fractions of the control batches, but both acids were detected in most of the batches made with enterococci. The more intense acid taste was found in the EFFB and control batches, the most bitter taste being found in the EFLB. Buttery, rancid and spicy flavors were more evident in the EFLB. The rancid and spicy flavors were positively correlated with the contents of volatile free fatty acids and long-chain free fatty acids. The cheeses of EFLB proved to be more crumbly than the EFFB, whereas the stickiness and deformability were higher in the EFFB. The batches with similar organoleptic characteristics to those of traditional cheese were the batch IV made with the less proteolytic strain of E. faecalis var. liquefaciens, and the batch VI made with a moderate lipolytic activity strain of E. faecalis var. faecalis.

Adenocarcinoma de la vesícula biliar / Adenocarcinoma of gallbladder

El adenocarcinoma de la vesícula biliar es el carcinoma más frecuente de las vías biliares extrahepáticas, ocupa el quinto lugar entre las neoplasias malignas del aparato digestivo y representa entre el 2 por ciento al 4 por ciento del total de tumores malignos. (1,2). Se destaca la asociación entre el carcinoma de la vesícula biliar y la litiasis vesicular en un 50 por ciento al 100 por ciento de los casos, por ello debe esperarse que un 3 por ciento de las vesículas operadas por litiasis puedan tener tambien un cáncer. Esta incidencia aumenta significativamente con la edad llegando al 10 por ciento en pacientes mayores de 65 años, aunque con variaciones regionales (3,4). Se presenta en éste trabajo la experiencia con 216 adenocarcinomas de la vesícula biliar en una población definida con posibilidades de seguimiento. Se analizan incidencia en relación al número de colecistectomías, aspectos clínicos de importancia, valor de los métodos de diagnóstico, presentación de una modificación del TNM, valoración del tratamiento efectuado y se presenta la sobrevida actuarial por estadío

Cáncer de la vesícula biliar. Nuestra experiencia de 252 casos y propuesta de una nueva estadificación / Carcinoma of the gallbladder. Report of 252 cases

Desde octubre de 1982 a diciembre de 1995 se realizaron 3571 operaciones biliares y se diagnosticaron 252 carcinomas de vesícula (siete por ciento).Ochenta por ciento fueron mujeres y la edad promedio fue de 71 años (rango de 40-91).Noventa por ciento de los pacientes presentaron litiasis asociada y treinta y cuatro por ciento demora en el tratamiento de la litiasis.Síntomas y signos más frecuentes fueron dolor abdominal (noventa por ciento),ictericia (cuarenta y cinco por ciento),naúseas y vómitos (treinta y seis por ciento),pérdida de peso (treinta por ciento).La correlación ecográfica fue buena con la presencia de litiasis,dilatación de los conductos biliares, engrosamiento de la pared vesicular y masa abdominal.La tomografía axial computada fue importante en matástasis hepáticas e invasión de estructuras adyacentes.El diagnóstico preoperatorio de cáncer vesicular fue realizado en 76 pacientes (treinta por ciento) y veinte por ciento fueron operados como colecistitis agudas.doce por ciento fueron resecados con cirugía radical.el tipo histológico más frecuente fue el adenocarcinoma (noventa y cuatro por ciento).Se presenta una estadificación TNM modificada.La sobrevida para el estadío 0-1 fue ochenta por ciento a 5 años, para el estadío II:cuarenta por ciento;III:treinta por ciento y para el estadío IV :cero

[Neonatal meningitis: study of 56 cases]. / Meningitis neonatal: Estudio de 56 casos.

OBJECTIVE: The objective of this study was to know the most common organisms causing neonatal meningitis in a defined region of southern Madrid, the developmental outcome of these babies and the risk factors associated with the prognosis. PATIENTS AND METHODS: This was an observational study of 56 cases of meningitis diagnosed in our Neonatal Service between 1988 and 1994. In order to study the handicaps of these babies, only those who were born before May 1993 were considered so that they had a corrected age of at least 2 years when the neurological evaluations were done. RESULTS: The most common causative organisms were group B Streptococcus (27%), E. coli (11%) and enteroviruses (9%). In the premature infants the leading organisms were E. coli and Candida albicans. The age at diagnosis was 8 +/- 6 days in the group of preterm infants (p = 0.002). The mortality was associated with the prematurity (risk ratio: 17.8), the isolation of a gram-negative organism in the cerebral fluid (RR: 3.3) and the presence of abnormal findings in cerebral ultrasound studies (RR: 12.7). Sequelae were associated with the presence of abnormal findings in cerebral ultrasound studies (RR: 24.7) or in the neurologic examination (R: 7) and with the presence of previous cerebral lesions (RR: 5.7). CONCLUSIONS: Neonatal ultrasound examination, as well as the gestational age, the causative organisms, the presence of a previous cerebral lesion and the neurological examination, seem to be very important in predicting the prognosis of these babies.

Main microbial flora present as natural starters in Cebreiro raw cow's-milk cheese (northwest Spain).

Thirty samples of Cebreiro, a fresh or short-time-ripened raw cow's-milk cheese produced in Northwest Spain, were analyzed for the presence of aerobic mesophilic bacteria, (AMC) lactic acid bacteria (LAB), enterococci and Micrococcaceae. Mean AMC and LAB counts exceeding 10(9)/g were higher than those reported for other fresh or short-time-ripened cheeses, although Micrococcaceae occurred in lower numbers (< 10(5)/g) than reported for other raw-milk cheeses. Out of a total of 126 LAB representation isolates, 59 were identified as enterococci (38 as Enterococcus faecalis) 30 as lactococci (24 as Lactococcus lactis subsp. lactis), 25 as leuconostocs (14 as Leuconostoc mesenteroides) and 6 were identified as mesophylic lactobacilli. The enterocci in general were more proteolytic and produced more diacetyl/acetoin than the other LAB groups lactic acid bacteria isolated. It seems that a starter for making Cebreiro cheese should contain these microorganisms so as to reproduce the typical characteristics of traditional raw milk Cebreiro cheeses.

Analysis of fermented milk products by near-infrared reflectance spectroscopy.

Fat, protein, and total solids in fermented milk were determined by near-infrared reflectance spectroscopy (NIRS). A set of 107 samples from diverse types of fermented milk (whole, skimmed, with added flavors, and without added flavors) were used to calibrate the instrument by modified partial least-square regression. Global calibration, using all samples, was more effective than specific calibrations using fewer samples of each type. Standard errors of a calibration were 0.071 for fat, 0.075 for protein, and 0.083 for total solids. Values of the correlation coefficient square (R2) were 0.997 for fat, 0.981 for protein, and 1.000 for total solids. Calibration was validated with an independent set of 34 samples of the same types. Standard errors of validation were 0.08, 0.14, and 0.25 for fat, protein, and total solids, respectively, and values of R2 for the regression of measurements by NIRS versus reference methods were 1.00 for fat and total solids and 0.94 for protein. When Standard 128 of the International Dairy Federation was used to compare NIRS results with those from reference methods, no significant differences were found (p = 0.05).

New intraluminal bypass tube for management of acutely obstructed left colon.

PURPOSE: A surgical technique is described for a new intracolonic bypass procedure in patients who underwent colonic surgery with an unprepared colon. METHODS: Resection and primary anastomosis was performed. The intraluminal bypass tube used was a latex condom. RESULTS: No clinical anastomotic leakage was noted. CONCLUSIONS: This is a safe, low cost, and uncomplicated procedure that decreases the risk of dehiscence and permits the performance of a high number of primary anastomosis.