Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment.

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment.

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Bone turnover markers and bone mineral density in children with haemophilia.

During childhood growth, bone undergoes modelling involving separate osteoblastic and osteoclastic processes. Markers of bone turnover circulate at high concentrations, parallel the childhood growth curve and correlate with height velocity. The aim of this study was to compare serum markers of bone turnover in children with haemophilia and normal bone mineral density (BMD) vs. those with low BMD. In a cross-sectional study, 69 children with haemophilia were evaluated, 45 children with normal spine BMD vs. 24 with low BMD. Lumbar spine BMD was determined using dual X-ray absorptiometry and Z-scores were calculated. Serum samples of markers of bone turnover, osteocalcin (bone formation) and C-telopeptide of type I collagen (bone resorption) were measured using ELISA. The mean BMD (g cm(-2) ) in the normal group was 0.656 ± 0.15 vs. 0.558 ± 0.12 in those with low BMD (P = 0.007), osteocalcin levels in children with normal BMD were 9.29 ± 4.97 vs. 7.06 ± 2.17 ng µL(-1) in the low BMD group (P = 0.012). C-telopeptide levels in the normal group were 1.06 ± 1.4 vs. 0.74 ± 0.3 ng mL(-1) in the low BMD group (P = 0.169). Our results showed that low osteocalcin levels predominated in the group with low BMD, which indicates a diminished osteoblastic bone formation activity while there were no differences with regard to bone resorption markers. Moreover, osteocalcin levels explain 10% of the variation of lumbar spine Z-score.

The potential role of the adipokine HMGB1 in obesity and insulin resistance. Novel effects on adipose tissue biology.

Discovery of the adipose tissue as a major source of signaling molecules almost three decades ago set a novel physiological paradigm that paved the way for the identification of metabolic organs as endocrine organs. Adipocytes, the main adipose tissue cell type, do not only represent the principal site of energy storage in form of triglycerides, but also produce a variety of molecules for short and long distance intercellular communication, named adipokines, which coordinate systemic responses. Although the best known adipokines identified and characterized hitherto are leptin and adiponectin, novel adipokines are continuously being described, what have significantly helped to elucidate the role of adipocyte biology in obesity and associated comorbidities. One of these novel adipokines is high-mobility group box 1 (HMGB1), a ubiquitous nuclear protein that has been recently reported to be dysregulated in obese dysfunctional adipocytes. Although the classical function of HMGB1 is related to inflammation and immunity, acting as an alarmin, novel advances evidence an active implication of HMGB1 in tissue remodeling and fibrosis. This review summarizes the current evidence on the mechanisms controlling HMGB1 release, as well as its role as a regulator of adipocyte function and extracellular matrix remodeling, with special emphasis on the potential of this novel adipokine as a target in the obesity treatment.

Chronic obstructive pulmonary disease in severe mental illness: A timely diagnosis to advance the process of quitting smoking.

BACKGROUND: This study has two main objectives: to describe the prevalence of undetected chronic obstructive pulmonary disease (COPD) in a clinical sample of smokers with severe mental illness (SMI), and to assess the value of the Tobacco Intensive Motivational Estimated Risk tool, which informs smokers of their respiratory risk and uses brief text messages to reinforce intervention. METHOD: A multicenter, randomized, open-label, and active-controlled clinical trial, with a 12-month follow-up. Outpatients with schizophrenia (SZ) and bipolar disorder were randomized either to the experimental group-studied by spirometry and informed of their calculated lung age and degree of obstruction (if any)-or to the active control group, who followed the 5 A's intervention. RESULTS: The study sample consisted of 160 patients (71.9% SZ), 78.1% of whom completed the 12-month follow-up. Of the patients who completed the spirometry test, 23.9% showed evidence of COPD (77.8% in moderate or severe stages). TIMER was associated with a significant reduction in tobacco use at week 12 and in the long term, 21.9% of patients reduced consumption and 14.6% at least halved it. At week 48, six patients (7.3%) allocated to the experimental group achieved the seven-day smoking abstinence confirmed by CO (primary outcome in terms of efficacy), compared to three (3.8%) in the control group. CONCLUSION: In this clinical pilot trial, one in four outpatients with an SMI who smoked had undiagnosed COPD. An intensive intervention tool favors the early detection of COPD and maintains its efficacy to quit smoking, compared with the standard 5 A's intervention.

Calmodulin binds to chick lens gap junction protein in a calcium-independent manner.

A biochemically active conjugate of calmodulin and tetramethylrhodamine isothiocyanate (CaM-RITC) was synthesized. When incubated with sections of chick lens, this conjugate bound to the surface membranes of lens fiber cells in the presence of absence of calcium. Incubation of lens sections with antibodies to gap junction protein of lens completely blocked the binding of the conjugate to cell membranes, whereas serum from nonimmunized animals or antibodies to others lens proteins reduced the binding only slightly. By means of a gel overlay procedure, 125I-labeled calmodulin was found to bind to the gap junction protein of lens, also in a calcium-independent manner. These results support the concept that calmodulin may interact with and regulate gap junctions in living cells.

[Arterial Hypertension register in private clinics in Venezuela: RHAVEN Study]. / Registro de Hipertensión Arterial en consultas privadas en Venezuela: Estudio RHAVEN.

INTRODUCTION: In Venezuela, no large studies have been conducted to determine the level of control of hypertension (HT). OBJECTIVE: The primary objective was to know the prevalence of controlled HT among hypertensive patients treated pharmacologically. MATERIALS AND METHODS: A cross-section study was conducted on patients 18years and older. RESULTS: A total of 4,320 patients were included. The prevalence of controlled hypertension was 52.6% (95%CI: 51.1-54.1%). The lack of control of HT was associated with diabetes (P<.001), hypertensive heart disease (P<.001), chronic kidney disease (P<.001), and peripheral arterial disease (P=.02). Non-compliance of treatment was also associated with uncontrolled HT (5.1% [117/2,274] in the controlled versus 43.2% [885/2,046] in the uncontrolled; (P<.001). CONCLUSION: The prevalence detected of controlled hypertension was 52.6%.

Incidence and evolution of sepsis-induced cardiomyopathy in a cohort of patients with sepsis and septic shock. / Incidencia y evolución de la miocardiopatía séptica en una cohorte de pacientes con sepsis y shock séptico.

OBJETIVE: The aim of this study was to establish the incidence of septic cardiomyopathy (SM) in patients with sepsis and septic shock, to describe its characteristics and testing its evolution. DESIGN: Prospective cohort study. PARTICIPANTS: We included 57 consecutive patients admitted to Intensive Care Unit, who met criteria of sepsis and septic shock. PRINCIPAL VARIABLES OF INTEREST: Clinical and biochemical variables were analyzed. An echocardiogram was performed in the first 24hours of admission, determining myocardial function parameters, and if the patients had left ventricular ejection fraction (LVEF)<50%) a second echocardiogram was performed. AMBIT: Intensive medical and surgical Care Service for Adults in University Hospital. RESULTS: The mean age of the patients was 62,1±16,3 years. 58% were males. 22.8% had left ventricular dysfunction. The mean LVEF in patients with MS was lower than those without SM (34.1±10.6 vs 60.7±6.94%, P<.001), with complete recovery, in survivors, after the acute event (LVEF at discharge 56.1±6.3%, P=.04). Patients with SM had higher levels of procalcitonin (47.1±35.4 vs 18.9±24.5; P=.02) and higher score on the Sequential Organ Failure Assessment (SOFA score) (9.91±3.82 vs 7.47±3.41; P=.037). Mortality was not significantly different between both groups [4 (30.8%) vs 4 (9.1%); P=.07]. CONCLUSIONS: SM is not uncommon and is related to a higher scores on the severity scales. In the survivors, LVEF normalized after the recovery of the acute event.

[Laparoscopic adrenalectomy. Reflections after 24 procedures]. / Adrenalectomía laparoscópica. Consideraciones a propósito de 24 procedimientos.

INTRODUCTION AND OBJECTIVES: Laparoscopic adrenalectomy has gained rapid recognition since publication of the first case in 1992. Currently it is the technique of choice for the surgical treatment of the adrenal gland. Our objective in this paper is to share our experience with this technique and offer some practical advice on how to approach it. MATERIALS AND METHODS: Between May 1998 and August 2006 we did a total of 24 laparoscopic adrenalectomies in 22 patients (15 men, 7 women). The right gland was removed in 13 cases and the left in 11. Surgery was bilateral in two cases (one was MEN II, the other bilateral cortical hyperplasia). Average age was 49.5 +/- 14.3 years (range 24 to 78). Clinical diagnosis was: Pheochromocytoma (n = 10), Cushing (n = 6), Conn (n = 4), metastases from lung carcinoma (n = 2) and non-functioning tumor (n = 2). For surgery, all patients were in total lateral decubitus with a pillow to increase the costal-iliac space. We used four trocars on the right side and three on the left. Abdominal access was by Hasson trocar after minilaparotomy. We kept pneumoperitoneal pressure below 12 mmHg; a Veress needle was not used for this procedure. RESULTS: Open surgery was required in one case. Time operation was between 59 and 400 minutes (mean 182 +/- 98 min.). In the first 12 cases average time was 261 +/- 77 minutes and in the final 12 cases was 103 +/- 21 minutes (p < 0.001). Tumour diameter was between 1.3 and 6 cm (mean 3.08 +/- 1.25 cm) and tumour weight was between 8 and 92g (mean 30.13 +/- 21 g). Except in one case with 600 ml blood loss, bleeding was less than 100 ml (n = 23, range: 10-100, mean 43.26 +/- 25ml). We only had intraoperative complications in two cases: perforation of the liver by the laparoscope retractor (at the beginning of the series) and injury to the spleen capsule. Both complications were resolved laparoscopically. Cases by histologic type were: nine cortical adenomas, nine pheochromocytomas, three nodular hyperplasias, two metastases from lung carcinoma, and one adrenal pseudocyst. Discharge from hospital was between three and five days (mean 3.62 +/- 0.82) with a statistical difference (p < 0.001) between twelve first cases and the last ones. CONCLUSIONS: The adrenal laparoscopic approach is currently the technique of choice for removing adrenal tumours although with malign tumours or over 7 cm in diameter there are some contraindications and disadvantages relative to open surgery. There is inevitably a learning curve but satisfactory results are quickly attainable.

Hypertension in Latin America: Current perspectives on trends and characteristics.

The region of Latin America, which includes Central America, the Caribbean and South America, is one that is rapidly developing. Signified by socio-economic growth, transition and development over the last few decades, living standards in countries like Brazil and Mexico have improved dramatically, including improvements in education and health care. An important marker of socio-economic change has been the epidemiological shift in disease burden. Cardiovascular disease is now the leading cause of death in Latin America, and the drop in prevalence of infectious diseases has been accompanied by a rise in non-communicable diseases. Hypertension is the major risk factor driving the cardiovascular disease continuum. In this article we aim to discuss the epidemiological and management trends and patterns in hypertension that may be specific or more common to Latin-American populations - what we term 'Latin American characteristics' of hypertension - via a review of the recent literature. Recognizing that there may be a specific profile of hypertension for Latin-American patients may help to improve their treatment, with the ultimate goal to reduce their cardiovascular risk. We focus somewhat on the countries of Brazil, Mexico and Venezuela, the experience of which may reflect other Latin American countries that currently have less published data regarding epidemiology and management practices.

[Laparoscopic radical prostatectomy. Only at centers of expertise]. / Prostatectomía radical laparoscópica. Sólo en centros de excelencia?

OBJECTIVES: To present and evaluate our experience and initial results in radical laparoscopic prostatectomy which we have been using for two and an half years in our General Hospital (covering a total population of 200.000 inhabitants). MATERIAL AND METHODS: Between December 2002 and August 2005, were selected 26 patients for radical laparoscopic prostatectomy (25 transperitoneal and 1 extraperitoneal). Mean age was 62.3 +/- 5.3 years (range 52-69). Mean PSA level was 9.16 +/- 4.20 ng/mL (range 5.26 to 24.3). Pre-operative classification was Tlc in 10 patients (38.4%), T2a in 8 (30.8%) and T2b in 8. Mean Gleason Score was 6 +/- 0.8 (range 4-7). Three patients had undergone preoperatively neo-adjuvant hormonal blockage (11.5%). Simultaneous bilateral inguinal lymphadenectomy was performed in two patients. In no case did we consider a nerve sparing approach. RESULTS: The procedure was accomplished in 20 patients. Mean follow-up was 12.4 +/- 8.6 months (range 3 - 34). There was no perioperative mortality. Conversion to open surgery was required six times in the ten first cases but not thereafter. Mean operating time for the whole series was 303 +/- 95 minutes (range 150-540) but with a distinct difference between the first fourteen and the last six cases: 332 +/- 92.58 versus 236.6 +/- 66.5 (p<0.02). Mean blood loss was 90.25 +/- 46.5 ml. There were early postoperative complications in 4 patients (15.38%). Final pathological staging was: T2a in three patients (15%), T2b (50%) in 10, T3a (15%) in three and T3b (20%) in four. Positive margins were found in three cases (11.5%): T2b, T3a and T3b. Mean hospitalisation time was 4.7 +/- 3.1 days. Provided there was no urinary leakage, the urinary catheter was removed at 12.7 +/- 2.7 days. Full continence at three months was achieved in 17 of the patients (85%) who had undergone the full laparoscopic procedure. CONCLUSIONS: Our previous experience in other major laparoscopic procedures has allowed us to perform radical laparoscopic prostatectomy with a fast learning curve even in a setting of a relatively low population. Initial long term results seem similar to those achieved with conventional surgery.

The plasma membrane of the rabbit lens cortical fiber. I. Isolation, characterization, and biosynthesis of two membrane intrinsic polypeptides.

Rabbit lens cortical fiber plasma membrane polypeptides were isolated and two membrane intrinsic proteins were characterized by SDS-PAGE. A polypeptide with a molecular weight of 26 kilodaltons is the major constituent of the plasma membrane. The molecular weight and antigenic properties of the other polypeptide studied are similar to polypeptides of cortical water-soluble alpha-crystalline. Biosynthesis of these two polypeptides was studied. After initially high rates, synthesis of both of these polypeptides decreased considerably and maintained a steady rate for the rest of the culture time.

Light transmittance as an index of cell volume in hippocampal slices: optical differences of interfaced and submerged positions.

Light transmittance (T) in the CA1 region of hippocampal slices was measured during exposure to media of various osmolarities to determine the utility of optical measurements as an index of changes in cell volume. In slices positioned at the gas-liquid interface, hypo-osmotic medium consistently produced a decrease in T and hyperosmotic medium produced an increase in T. The magnitude of deltaT was graded as a function of the strength of osmotic change. All changes in T were reversible upon return to isosmotic medium. In contrast, osmotically induced changes in T in submerged slices were consistently opposite in direction to those observed in slices at the interface. The magnitude and direction of deltaT could be altered by systematic variation of the level of the bathing medium within the same chamber, indicating that both extrinsic optical properties of various interfaces, such as refraction and reflection, and intrinsic optical properties of the tissue contribute to the observed T. Spectral measurements eliminated the possibility that osmotically induced deltaT was the result of changes in light absorbance by intrinsic chromophores such as cytochromes or hemoglobin. The results show that measurements of deltaT can be a useful index of changes in cell volume in brain slices, provided that the level of the bath remains constant.

Expression of interleukin-1 beta, tumor necrosis factor alpha, interleukins-6, -10 and -4, and metalloproteases by freshly isolated mononuclear cells from early never-treated and non-acute treated rheumatoid arthritis patients.

OBJECTIVE: To determine IL-1 beta, TNF alpha, IL-6, IL-4, IL-10, MMP-1, MMP-3 and MMP-13 expression by freshly isolated peripheral blood (PBMC) and synovial fluid mononuclear cells (SFMC) in early, never-treated (ENT-RA) and non-acute, treated rheumatoid arthritis (NAT-RA) patients. To elucidate whether excessive or inadequate interleukin (IL) and metalloprotease (MMP) expression is influenced by the disease duration. METHODS: Fourteen RA patients, 7 with early RA (< 1 year of evolution) never treated with corticosteroids or disease-modifying antirheumatic drugs, and 7 patients with non-acute RA (> 2 years of evolution) treated with disease-modifying antirheumatic drugs, were studied by ELISA and quantitative and semiquantitative RT-PCR. A group of 14 healthy subjects matched for sex and age was included. RESULTS: No statistically significant difference in the protein or transcript levels for the cytokines of interest was found between the ENT-RA and NAT-RA groups. The cytokine mRNA expression by freshly isolated PBMC and SFMC in both groups was as follows: IL-1 beta > TNF alpha > IL-10 > IL-6, with no mRNA IL-4 expression. In contrast, cytokine serum levels in ENT-RA and NAT-RA patients were detected in inverse order as follows: IL-6 > IL-10, while IL-1 beta, TNF alpha and IL-4 were undetectable. MMP-3 mRNA expression by the PBMC of NAT-RA patients was statistically different to that in ENT-RA patients. Similar levels of mRNA expression of MMP-1, MMP-3 and MMP-13 by the PBMC and SFMC in both RA groups were observed. CONCLUSIONS: A close equilibrium between MMP and pro/anti-inflammatory cytokine production is observed in ENT-RA and NAT-RA patients. This balance is apparently not influenced by the length of the disease. Highly sensitive methods such as quantitative RT-PCR and ELISA, and even studying freshly isolated MC, showed sustained cytokine secretion at the local level (synovial fluid/SFMC) and scarce translation at the peripheral level (serum/PBMC). Expression of MMP mRNA needs to be further evaluated in order to know whether their peripheral expression reflects their local activity in RA patients.

Real-time frequency domain temperature and oxygen sensor with a single optical fiber.

The combined excited-state phosphorescence life-times of an alexandrite crystal and platinum tetraphenylporphyrin Pt(TPP) in a single-fiber sensor are used to monitor temperature and oxygen concentration in the physiological range from 15-45 degrees C and 0-50% O2 with precision of 0.24 degree C and 0.15% O2 and accuracy of 0.28 degree C and 0.2% O2. A 500-micron cubic alexandrite crystal bound to the distal end of a 750-micron-diameter optical fiber core and the Pt(TPP) coated circumferentially with a length of 1 cm from the end of the same fiber are excited with pulsed super-bright blue LED light. This apparatus uses a 125-kHz sampler for data acquisition and frequency domain methods for signal processing. The instrument amplifies both the dc and ac components of the photomultiplier output and band limits the signal to 20 kHz. The fundamental frequency of the excitation is set to 488.3 Hz and the highest harmonic used is the 35th. This bandlimited signal is sampled and averaged over a few hundred cycles in the time domain. The frequency domain representation of the data is obtained by employing fast Fourier transform algorithms. The phase delay and the modulation ratio of each sampled harmonic are then computed. At least four log-spaced harmonic phases or modulations are averaged before decoding the two lifetimes of temperature and oxygen phosphorescent sensors. A component of zero lifetime is introduced to account for the excitation backscatter leakage through optical interference filters seen by the photodetector. Linear and second-order empirical polynomials are employed to compute the temperatures and oxygen concentrations from the inverse lifetimes. In the situation of constant oxygen concentration, the lifetime of Pt(TPP) changes with temperature but can be compensated using the measured temperature lifetime. The system drift is 0.24 degree C for the temperature measurement and 0.59% for the oxygen concentration measurement over 30 h of continuous operation. The instrumentation and methods allow for 6-s update times and 90-s full-response times.

NCAM of the mammalian lens.

NCAM is present in the plasma membranes of human and rat lens epithelial cells and superficial fiber cells. The predominant isoform in epithelial cells is NCAM 140, while NCAM 120 appears only in the superficial fiber cells. The immunofluorescence patterns are consistent with a decreasing concentration of NCAM associated with fiber cell differentiation.

Lipid composition of chick lens fiber cell gap junctions.

Chick lens fiber cell gap junctions were isolated to homogeneity by the urea-deoxycholate method, characterized ultrastructurally and biochemically, and their lipid composition determined by quantitative thin layer chromatography (TLC). The junctions were estimated to comprise about 52% of the lens fiber plasma membrane. Unlike the junctions of other organs, the lens gap junctions were found to contain sphingomyelin. The cholesterol/phospholipid molar ratio was 2.1 for total fiber membranes but 3.1 for the fiber gap junctions. The levels of major phospholipids in decreasing order were SPH, PC, PE, PI for fiber junctions and PE, SPH, PC, PI for total fiber membranes. The gap junctions were found to contain about 57% of the total fiber cholesterol and 53% of the total fiber sphingomyelin. The high cholesterol and sphingomyelin content suggests that lens fiber gap junctions constitute highly rigid membrane regions conferring significant constraints to the movement of their intramembrane particles (connexons) in the plane of the membrane. The findings help to explain the resistance to the crystallization of their connexons, observed so far only in lens gap junctions.

Human beta crystallins: regional and age related changes.

The composition of human beta-crystallins displayed specific changes with age and region of the lens. 27 kD and 29 kD human beta-crystallin subunits were singled out for study. The 29 kD beta-crystallin subunit constituted approximately 10% of the total lens crystallins at 8 months of fetal life. Its accumulation decreased steadily to 3.3% during postnatal year 1, to 0.5% by year 5 and to 0.3% thereafter. At all postnatal ages, however, it persisted mainly in the superficial fibers. Thus in a 17-years old lens it made up 1.3% of the superficial fiber soluble protein but was already absent from deep cortical and nuclear fibers. The 27 kD subunit increased steadily from 3.5% at 8 months fetal to 7% at year 5; it then decreased steadily to 1.2% in the 86-year old lens. It persisted in all regions of the lens but decreased markedly in the deep cortical and nuclear fibers with increasing age beginning at 5-17 years of age. Studies on the oligomeric structure of human beta-crystallin must take into account age-related changing quantitative patterns in the subunit polypeptide composition of this lens protein.

Reversal of the limited proteolysis of MP26 during the reversal and prevention of the galactose cataract in rat lenses.

The reversal and prevention of the galactose-induced cataract in rats were employed to study their effects on the acceleration of the limited proteolysis of MP26 into MP23-24 previously observed in cataractous lenses of galactose-fed animals. Lenses of rats on a cataract reversal-diet demonstrated the reversal of MP23-24 and MP26 levels to control levels in the clearing cortical areas but not in remaining cataractous nuclear areas. Acceleration of the limited proteolysis of MP26 was observed in the nucleus but not the cortex in the clear lenses of animals on a cataract prevention-diet. The results demonstrated that the limited proteolysis of MP26 may form part of a gradual aging process that although not directly (causally) related to cataractogenesis may at least be accelerated by cataractogenic agents or conditions.

Limited proteolysis of MP26 in lens fiber plasma membranes of the U18666A-induced cataract in rats.

Most of the animals treated with U18666A every other day beginning at one-day of age developed permanent nuclear cataracts by 3-4 weeks of age. Lens fiber plasma membranes were isolated from cortical and nuclear areas of untreated controls, treated but clear, and treated cataractous lenses, and analyzed by SDS-PAGE. MP26 was the major intrinsic polypeptide in the plasma membranes of both cortical and nuclear fibers of control lenses. MP26 was largely replaced by MP23-24 in the plasma membranes of nuclear fibers of treated but clear lenses, and in the membranes of both cortical and nuclear fibers of cataractous lenses.