Internal Fiber Research Articles

Three-dimensional cellular architecture of the flagellar pocket and associated cytoskeleton in trypanosomes revealed by electron microscope tomography

This study uses electron tomography linked to a variety of other EM methods to provide an integrated view of the flagellar pocket and basal body area of the African trypanosome procyclic trypomastigote. We reveal the pocket as an asymmetric membranous 'balloon' with two boundary structures. One of these - the collar - defines the flagellum exit point. The other defines the entry point of the flagellum into the pocket and consists of both an internal transitional fibre array and an external membrane collarette. A novel set of nine radial fibres is described in the basal body proximal zone. The pocket asymmetry is invariably correlated with the position of the probasal body and Golgi. The neck region, just distal to the flagellum exit site, is a specialised area of membrane associated with the start of the flagellum attachment zone and signifies the point where a special set of four microtubules, nucleated close to the basal bodies, joins the subpellicular array. The neck region is also associated with the single Golgi apparatus of the cell. The flagellar exit point interrupts the subpellicular microtubule array with discrete endings of microtubules at the posterior side. Overall, our studies reveal a highly organised, yet dynamic, area of cytoplasm and will be informative in understanding its function.

The study of water behaviour in regenerated cellulosic fibres by low-resolution proton NMR

Regenerated cellulosic fibres and comparative materials were studied in the hydrated state by low-resolution proton NMR. Experiments at variable pH and temperatures have shown that the shortened T2 relaxation times of water within fully swollen cellulosic fibres are dominated by proton exchange with accessible cellulose hydroxyl groups. Proton exchange is accelerated by both acid and base catalysis, with relaxation data used to estimate rate constants for acid, base and neutral mechanisms. Complementary deuterium exchange measurements suggest that accessible cellulose regions below the immediate water interface may not contribute effectively to the proton exchange relaxation mechanism, with two-site relaxation models sensitive only to the direct pore surface area. Differences between surface-relaxing water and deuterium-exchanging water can therefore be used to determine an apparent depth of the accessible cellulose, which is greater for viscose and modal compared to lyocell. However, from relaxation data lyocell has a higher pore surface area. This work also confirmed that water interacting with accessible cellulose experiences motional restriction, allowing an intra-molecular dipolar contribution to relaxation. However, in the fully swollen state water molecules are diffusing rapidly between all internal fibre environments and there is no evidence of specific binding.

Closed Lateral Internal Sphincterotomy Versus Anal Sphincterolysis for Chronic Anal Fissure

Purpose:The aim of this randomized, prospective study was to compare the results of closed lateral internal sphincterotomy with the authors' innovative approach of finger fragmentation of internal sphincter fibers, termed sphincterolysis, in the treatment of chronic anal fissure.Patients and Methods:Adult patients with chronic anal fissures were randomly assigned to undergo closed lateral sphincterotomy or sphincterolysis. The patients were reexamined at 4 and 54 weeks. Postoperative pain, complications, and fissure healing were prospectively assessed.Results:Of the 85 patients randomly assigned, four were lost to follow-up leaving behind 40 sphincterotomy and 41 sphincterolysis patients for assessment. At 4 weeks postoperatively, fissures were healed in 95% of patients in both groups. At the 4-week follow-up, three patients from the closed sphincterotomy group and two patients from the sphincterolysis group reported deterioration in continence. Of these five patients, four had recovered at the 54-week follow-up, while the remaining patient from the sphincterotomy group continued to have a defective continence. Both groups had significantly lower anal resting pressures compared with their corresponding preoperative levels (p = 0.005 and p = 0.004) at the last follow-up.Conclusion:The procedure of sphincterolysis seems to be equally effective when compared with closed sphincterotomy. It is safe and easy to perform having less incidences of postoperative complication with no significant continence defect.

Behavior of Short Carbon Fibers in Cfiber/Si3N4 Composites by Hot Pressed Sintering

Cfiber/Si3N4 composites were prepared by introducing short carbon fibers into a mixture of silicon nitride and sintering additives (La2O3—Y2O 3) by hot pressed sintering. The effects of fibers on microstructure and mechanical properties of composites were discussed after higher temperature sintering. The corrosion of carbon fibers was manifested in two characteristic ways: (1) the internal fiber had exfoliative structure and some serious cavities were easily found at the interfaces between Si3N4 matrix and carbon fibers; (2) the fiber surface was covered by β-Si3N 4 crystallites. When the fiber content varied from 0 to 1 wt%, the fracture toughness increased from 6.6 MPa · m1/2 to 8.01 MPa· m 1/2. The flexural strength decreased from 638.14 MPa to 584.63 MPa with the rise of short fiber content.

Beef sausage structure affected by sodium chloride and potassium lactate

A histological and ultrastructural study was conducted to characterize changes in the muscle fibre structure of three fresh sausage preparations, depending on meat composition, sodium chloride (NaCl) and potassium lactate (K-lactate) contents. After addition of 0.8% and 1.6% NaCl, 65% and 51%, respectively, of the area observed showed well preserved fibres (histological data). The altered regions presented a large disorganization of the myofilaments and a solubilization of the sarcolemma and of the Z lines. K-lactate addition had no marked effects on meat structure. The preparation containing some sheep meat was more sensitive to salt than the others containing only bovine meat. The level of alteration was much lower than those obtained in pork meat in another study. Technological conditions used to modify the internal muscle fibre structure during sausage processing depend on the species used. Therefore, the classification of the sausage preparation to “meat preparation” or “meat product” under the EU regulation (EC) No. 853/2004 (which assign meat preparations to meat if the product has undergone a process insufficient to modify the internal muscle fibre structure of the meat) must be systematically controlled when changing the meat sausage composition.

Light fiber optic probe for measuring internal breakthrough of rare earth ion-labelled microspheres in porous media under unsaturated conditions

Application of minimally invasive probes for measuring fluorescent labelled colloids inside sand columns resulted in internal breakthrough curves at given points, that provided information about mass distributions without disrupting the column. Until now, light fiber optic probes were used in combination with organic fluorophores like fluoresceine or rhodamine, which have inherent disadvantage, such as comparably small Stoke's shifts and quenching at high concentrations. These may be overcome using rare earth ion complexes to label colloidal particles like microspheres (MS). Furthermore, these dyes have large fluorescent lifetimes compared to organic fluorophores, which readily allows the elimination of background fluorescence using time-resolved spectroscopy. We demonstrate the novel application of rare earth ion-labelled microspheres as colloidal tracers in column experiments under unsaturated conditions in porous media in coupling with a detection setup based on internal light fiber optic probes. Differences in mass budgets between internal detection and detection at the outlet were confirmed afterwards by invasive refurbishment of the column matrix.

Effects of methane concentration on diamond spherical shell films prepared by DC-plasma jet CVD

Diamond spherical shell films with different methane concentrations were deposited by DC plasma jet CVD method. The morphology, impurities, internal fiber texture and surface roughness of diamond film were investigated by scanning electron microscopy, Raman spectroscopy, X-ray diffraction and roughness profile meter respectively. The results show that, at the beginning of diamond nucleation, diamond crystallites orientation was random, and influence of CH 4 concentration was negligible. At a low CH 4 concentration (1%) and the substrate temperature of 850 °C, high quality diamond film was prepared. The film structure was polycrystalline and (111) face was dominant. When CH 4 concentration was increased, diamond film has more local clusters, amorphous graphite. Thus, higher CH 4 concentration has negative influence on preparing high quality diamond film.

PLLA biodegradable scaffolds for angiogenesis via Diffusion Induced Phase Separation (DIPS)

A critical obstacle in tissue engineering is the inability to maintain large masses of living cells upon transfer from the in vitro culture conditions into the host in vivo. Capillaries, and the vascular system, are required to supply essential nutrients, including oxygen, remove waste products and provide a biochemical communication “highway”. For this reason it is mandatory to manufacture an implantable structure where the process of vessel formation – the angiogenesis – can take place. In this work PLLA scaffolds for vascular tissue engineering were produced by dip-coating via Diffusion Induced Phase Separation (DIPS) technique. The scaffolds, with a vessel-like shape, were obtained by performing a DIPS process around a nylon fibre whose diameter was 700 μm. The fibre was first immersed into a 4% PLLA dioxane solution and subsequently immersed into a second bath containing distilled water. The covered fibre was then rinsed in order to remove the excess of dioxane and dried; finally the internal nylon fibre was pulled out so as to obtain a hollow biodegradable PLLA fiber. SEM analysis revealed that the scaffolds have a lumen of ca. 700 μm. The internal surface is homogeneous with micropores 1–2 μm large. Moreover, a cross section analysis showed an open structure across the thickness of the scaffold walls. A cell culture of endothelial cells was carried out into the as-prepared scaffolds. The result showed that cells are able to grow within the scaffolds and after 3 weeks they begin to form a “primordial” vessel-like structure.

Fractal dimension of down fibre assemblies

As porous media materials, down fiber assemblies have excellent heat insulating and are widely used in the thermal products. The internal microstructures and fibers arrangement strongly influence heat conduction in down fiber assembly. This work presents a unified treatment using the tool of ‘‘local fractal dimensions’’ to describe the geometric complexity of the relative fibers arrangement in the down fiber assembly.

Effects of gas gap type on structural morphology and performance of hollow fibers

Polyethersulfone hollow fiber membranes were prepared by the dry/wet spinning technique under different gas gaps, namely, air, oxygen, nitrogen, carbon dioxide and argon. All spinning parameters were maintained the same. The effects of the gas type on the morphological properties of the hollow fibers were studied in terms of atomic force microscopy and solute transport using ultrafiltration of the non-ionic solutes; i.e. polyethylene glycol and polyethylene oxide of different molecular weights. Pore size, nodule size and roughness parameters of both the internal and external hollow fiber surfaces were determined by atomic force microscopy. Pure water permeation, performance ratio, mean pore size, pore size distribution, pore density, porosity and molecular weight cut off were obtained from solute transport analysis. The studied polyethersulfone hollow fiber membranes could be divided into two groups. A group of hollow fibers prepared under gases exhibiting higher molecular mass and lower thermal conductivity like carbon dioxide and argon and a group of hollow fibers prepared under the other gases (air, oxygen and nitrogen) having lower molecular mass and higher thermal conductivity. Hollow fiber membranes prepared under gas gap type having high molecular mass and low thermal conductivity exhibit greater pore size, nodule size and roughness of the external surface than the other fiber membranes, whereas no significant change was detected in the structural parameters of the internal surface of all prepared hollow fibers. Differences in hollow fiber membrane permeability and separation performance were also observed depending on the gas type used.

Prenatal and Adolescent Exposure to Tobacco Smoke Modulates the Development of White Matter Microstructure

Prenatal exposure to maternal smoking has been linked to cognitive and auditory processing deficits in offspring. Preclinical studies have demonstrated that exposure to nicotine disrupts neurodevelopment during gestation and adolescence, possibly by disrupting the trophic effects of acetylcholine. Given recent clinical and preclinical work suggesting that neurocircuits that support auditory processing may be particularly vulnerable to developmental disruption by nicotine, we examined white matter microstructure in 67 adolescent smokers and nonsmokers with and without prenatal exposure to maternal smoking. The groups did not differ in age, educational attainment, IQ, years of parent education, or symptoms of inattention. Diffusion tensor anisotropy and anatomical magnetic resonance images were acquired, and auditory attention was assessed, in all subjects. Both prenatal exposure and adolescent exposure to tobacco smoke was associated with increased fractional anisotropy (FA) in anterior cortical white matter. Adolescent smoking was also associated with increased FA of regions of the internal capsule that contain auditory thalamocortical and corticofugal fibers. FA of the posterior limb of the left internal capsule was positively correlated with reaction time during performance of an auditory attention task in smokers but not in nonsmokers. Development of anterior cortical and internal capsule fibers may be particularly vulnerable to disruption in cholinergic signaling induced by nicotine in tobacco smoke. Nicotine-induced disruption of the development of auditory corticofugal fibers may interfere with the ability of these fibers to modulate ascending auditory signals, leading to greater noise and reduced efficiency of neurocircuitry that supports auditory processing.

Thermal cycling response behavior of ceramic matrix composites under load and displacement constraints

Thermal cycling response of a two-dimensional carbon fiber reinforced SiC matrix composite (2D C/SiC) to load constraint (LC) and to displacement constraint (DC) in an oxidizing environment was investigated. During thermal cycling between 700 and 1200 °C, a constraint strain with a 0.208% range and a constraint stress with a 180 MPa range were, respectively, generated on the composites in LC and DC. It was found that with increasing cycles, the constraint strain increased in LC and the constraint stress decreased in DC. After 50 cycles, in contrast to the as-received composite materials, the as-cycled composites suffered greater loss in mechanical properties: the residual strength and failure strain are 204 MPa and 0.49% for the LC tested samples, and 223 MPa and 0.64% for the DC tested samples, respectively. Microstructural observations indicated that the LC could develop thermal microcracks and assist in oxidizing the internal fibers, whereas the DC reduced crack propagations and fiber oxidation because of decreasing tensile and increasing compressive stresses.

Strain and Temperature Discrimination Using Concatenated High-Birefringence Fiber Loop Mirrors

In this letter, a new configuration for simultaneous strain and temperature discrimination is presented using two concatenated high-birefringence (Hi-Bi) fiber loop mirrors. The first loop mirror includes a Hi-Bi photonic crystal fiber, while the second one contains a length of internal elliptical cladding fiber. It is shown that by monitoring the wavelength and optical power of one of the peaks of the system spectral transfer function, it is possible to obtain information that permits the simultaneous measurement of strain and temperature.

Internal anal sphincterolysis for chronic anal fissure: a prospective, clinical, and manometric study

Background The author proposes a technique of finger fragmentation of internal anal sphincter fibers to relieve anal sphincter spasm in patients with chronic anal fissures. This prospective study evaluates the clinical and functional outcome in a group of patients with chronic anal fissures. Materials and methods Forty-five patients suffering from chronic anal fissure underwent the procedure termed “sphincterolysis.” Anal manometry was performed prior to and at 6 and 24 months after treatment. Anal incontinence was evaluated by means of a continence score. Patients were asked to rate the level of satisfaction at the last follow-up. Results Forty-four patients completed the study. Symptom control was achieved in 7. 4 ± 3 days in 91% patients whose fissures had healed when examined 4 weeks after the procedure. In 38 of these patients, pain was relieved at the time of first postoperative defecation. Recurrence of fissure was observed in 1 patient at the 6-month follow-up. Three patients had minor continence disturbances, which resolved within 6 months. Anal manometry before and after the procedure showed a significant reduction in mean resting pressure (MRP) ( P < .001), while the maximum squeeze pressure before and after the treatment did not reached a statistically significant reduction. As regards satisfaction grading, 79.5% of patients were highly satisfied with the procedure, while another 16% of patients rated the procedure as good. Conclusion Internal anal sphincterolysis seems to be an effective, safe and easy procedure, which decreases anal resting pressure and achieves good symptom control with high patient satisfaction.

Mid‐term Results of Stapled Hemorrhoidopexy for Third‐ and Fourth‐degree Hemorrhoids—Correlation with the Histological Features of the Resected Tissue

Stapled hemorrhoidopexy is used to remove a circumferential strip of mucosa and submucosa about 4 cm above the dentate line, in order to restore the correct anatomical relationships of the anal canal structures. We evaluated the histological features of the resected tissue obtained after stapled hemorrhoidopexy with correlation to the short-term and mid-term results. This retrospective study evaluated 234 cases of stapled hemorrhoidopexy. Data concerning postoperative bleeding, anal pain, incontinence, stenosis, and recurrence of hemorrhoids were collected from hospital and outpatient clinic records. Histologic slides were examined for the type of epithelium, presence of muscle fibers, nerve endings, and degree of vascular ectasia. Some 52% of the biopsies revealed on the surface a combination of glandular with squamous epithelium, meaning a stapling line at the level of the transitional zone/dentate line. Smooth muscle fibers were more frequent as the stapling line approached the level of the dentate line/transitional zone (p = 0.0028). Internal sphincter fibers were present in 36% of the cases, yet there were no cases of anal incontinence. Inclusion of merely squamous epithelium in the resected tissue correlated with severe postoperative pain persisting one week after surgery (p < 0.0001), whereas the concurrent presence of squamous and glandular epithelium correlated only with severe pain on the first postoperative day (p = 0.018). Nerve endings were more frequent in patients with anal pain one week after surgery (p = 0.02). The rate of recurrence of symptoms was 3%, which did not correlate with any of the histological parameters tested. Though stapled hemorrhoidopexy is performed according to well-established technical guidelines, it is too difficult to be standardized.

Relationship between efficiency and pedal rate in cycling: significance of internal power and muscle fiber type composition

Cycling was performed to test the following two hypotheses: (1) muscular efficiency is unrelated to pedal rate (61, 88, and 115 r.p.m.) for a group of subjects with a wide range of slow twitch (ST) fibers in spite of decreasing whole-body efficiency and (2) muscular efficiency correlates positively with % ST muscle fibers, and this correlation is more pronounced at low pedal rates than at high pedal rates. Whole-body gross efficiency decreased from 20-22% at 61 r.p.m. to 15-18% at 115 r.p.m. Mean muscular efficiency for all subjects (n=16) was approximately 26%, with delta efficiency being constant and muscular efficiency (taking internal power into account) slightly increasing with pedal rate. Muscular efficiency correlated positively (R(2)=0.25) with % ST fibers (21-97% ST in m. vastus lateralis) at 115 r.p.m. while not at 61 and 88 r.p.m. In conclusion, the decrease in whole-body gross efficiency with increasing pedal rate was not explained by a decrease in muscular efficiency, and supported increase in internal power to account for the increase in metabolic power with increasing pedal rate. Furthermore, differences between individuals in muscle fiber type composition affected muscular efficiency, which correlated positively with % ST muscle fibers during fast pedalling.

Consumo e digestibilidade dos nutrientes em bovinos alimentados com dietas à base de volumosos tropicais

Objetivou-se determinar os consumos de MS, PB, EE, CT, FDN e CNF e as digestibilidades aparentes totais e parciais desses nutrientes em bovinos alimentados com dietas à base de silagens de milho e de capim-elefante e feno de capim-Tifton 85. Os volumosos compuseram 90% da MS das dietas, as quais foram suplementadas com 10% de farelo de soja. Foram utilizados seis bovinos fistulados no rúmen e abomaso (peso inicial de 351 kg) em um delineamento em quadrado latino 3 x 3 duplo, simultâneos. Cada período experimental constou de 16 dias, sendo os 10 primeiros destinados à adaptação dos animais e os seis dias restantes para coleta de amostras de fezes e digesta abomasal. Utilizou-se a fibra em detergente neutro indigestível (FDNi) como indicador do fluxo de MS abomasal e fecal. Embora as dietas à base de silagem de milho e de feno de capim-Tifton 85 não tenham diferido quanto à ingestão de MS, a dieta à base de silagem de milho permitiu maior ingestão de NDT. A dieta de feno de capim-Tifton 85 promoveu promoveu maior consumo de FDN (4,52 kg/dia), enquanto aquela com silagem de milho resultou em maior ingestão de CNF (1,95 kg/dia). A dieta com silagem de milho proporcionou maior digestibilidade aparente total de MS (66,3%), MO (68,9%), FDN (55,7%) e CT (68,2%). O rúmen foi o principal local de digestão dos carboidratos totais e da FDN para todas as dietas. Considerando a relação inversa entre a digestibilidade total da matéria seca e a ingestão de FDNi, pode-se inferir que essa última fração pode ser utilizada na estimativa da digestibilidade de gramíneas tropicais. A estimativa da digestão verdadeira dos CNF foi de 96,6% para as dietas avaliadas.

Magnetically-Guided Self-Assembly of Fibrin Matrices with Ordered Nano-Scale Structure for Tissue Engineering

The development of effective biological scaffold materials for tissue engineering and regenerative medicine applications hinges on the ability to present precise environmental cues to specific cell populations to guide their position and function. Natural extracellular matrices have an ordered nano-scale structure that can modulate cell behaviors critical for developmental control, including directional cell motility. Here we describe a method for fabricating fibrin gels with defined architecture on the nanometer scale in which magnetic forces are used to position thrombin-coated magnetic micro-beads in a defined 2-dimensional array and thereby guide the self-assembly of fibrin fibrils through catalytic cleavage of soluble fibrinogen substrate. Time-lapse and confocal microscopy confirmed that fibrin fibrils nucleate near the surface of the thrombin-coated beads and extend out in a radial direction to form these gels. When controlled magnetic fields were used to position the beads in hexagonal arrays, the fibrin nano-fibrils that polymerized from the beads oriented preferentially along the bead--bead axes in a geodesic (minimal path) pattern. These biocompatible scaffolds supported adhesion and spreading of human microvascular endothelial cells, which exhibited co-alignment of internal actin stress fibers with underlying fibrin nano-fibrils within some membrane extensions at the cell periphery. This magnetically-guided, biologically-inspired microfabrication system is unique in that large scaffolds may be formed with little starting material, and thus it may be useful for in vivo tissue engineering applications in the future.

The value of 3 T MR diffusion tensor fiber tractography study of association fasciculus of normative human in vivo primarily

Objective To exhibit the fibers of association fascicules,aims at demonstrating the association fibers of brain with diffusion tensor fiber tracking technique.Methods Conventionality MRI, diffusion tensor imaging(DTI)and diffusion tensor fiber tractography(DT-FT)were performed in twenty healthy subjects,including eighteen right-handed(sixteen men and four women)and two left-handed(one male and one female)by 3 T Siemens Trio 2003 T MRI.To select arcuate faseicules,inferior longitudinal fascicules,frontal-occipital fascicules,corpus callosum,posterior limb of internal capsule and external capsule as seeds used to track fibers.Results Diffusion tensor fiber tracking exhibited bundles of external capsule left mean fibers were 308 bundles,right fibers were 307 bundles(t=0.138,P0.05),frontal- occipital tracks left mean fibers were 115 bundles,right fibers were 110 bundles(t=1.174,P0.05),and their fractional anisotropy(FA)valueextemal capsule mean FA left was 0.361,the fight was 0.362 (t= -0.184,P0.05).Frontal-occipital tracks mean fractional anisotropy left was 0.352,the right was 0.351(t= -0.816,P0.05).The difference between both sides were statistically insignificant(P 0.05).The posterior limb of internal capsule left mean fibers were 249 bundles,fight fibers were 257 bundles(t= -0.818,P0.05),arcuate fasciculesleft mean fibers were 198 bundles,right fibers were 204 bundles(t= -0.465,P0.05)fibers difference between both sides were statistically insignificant (P0.05),but the individual difference was significant,and their fractional anisotropy difference between both sides(posterior limb of internal capsule mean FA left was 0.450,the right was 0.444(t=2.771,P 0.01).Arcuate fascicules mean FA left was 0.386,the right was 0.375(t=1.912,P0.05)were statistically significant(P0.05).Inferior longitudinal fascicules left mean fibers were 138 bundles,right fibers were 116 bundles(t=1.739,P0.05)and fractional anisotropy difference between both sides mean FA left was 0.377,the right was 0.359(t=2.606,P0.01)were statistically significant(P0.05). There may be a new association fascicules inner 4 brain lobes,the fascicules in the same side hemisphere, associated with the frontal,temporal,parietal and occipital lobes,named the Frontal-Parietal-Occipital bundles(FPOB).The fibers left mean fibers were 126 bundles,right fibers were 133 bundles(t= -0.791, P0.05).Mean FA left was 0.369,the right was 0.370(t= -0.178,P0.05),difference between both sides was statistically insignificant(P0.05).But the individual difference was significant.Some of them were the left larger than the right side.The frontal parts kept in touch with the Broca area of the left posterior of inferior frontal gyre.Conclusions There is individual difference both sides of association fascicules. There may be a new fiber bundle in the hemisphere,and associate with frontal lobe,temporal lobe,parietal lobe and occipital lobe.

Internal Capsule Size in Good-Outcome and Poor-Outcome Schizophrenia

Converging lines of research suggest that white matter abnormalities may be central to the pathophysiology of schizophrenia. The purpose of this study was to examine regional white matter in the anterior limb of the internal capsules in patients with schizophrenia. The authors obtained high-resolution magnetic resonance imaging in 106 patients with schizophrenia and 42 age and sex-matched healthy comparison subjects. The area of the anterior limb of the internal capsule was measured at five proportionately spaced dorsal-to-ventral levels. Schizophrenia patients were divided into good-outcome and poor-outcome groups, based on longitudinal analysis of self-care deficits. Patients with poor-outcome had significantly smaller dorsal areas than healthy comparison subjects, but good-outcome patients did not differ from healthy comparison subjects. Larger relative volumes of the caudate, putamen, and thalamus tended to be associated with relatively larger volumes of the internal capsule in healthy comparison subjects and good-outcome patients, consistent with the known frontal-striatal-thalamic pathways. Larger ventricles were associated with smaller internal capsules, particularly in healthy comparison subjects. The findings suggest disruption of internal capsule fibers in poor-outcome patients with schizophrenia. These abnormalities may be independent of other structural changes in schizophrenia.