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Hydrogenated amorphous silicon (a-Si : H) layers deposited by chemical vapour deposition provide an attractive route to achieve high-performance crystalline silicon (c-Si) solar cells due to their deposition at low temperatures and their superior passivation quality. Hydrogen certainly plays an additional crucial role by passivating the dangling bonds, and thus improving the electrical and optical properties. In this work, we present the variation of the effective lifetime with the hydrogen dilution ratio R  =  (H2/SiH4). We find that at lower hydrogen dilution rates (R  <  2), the polymerization reaction of silane molecules in the plasma bulk as well as the excess of dihydride (Si–H2) incorporation in as-deposited layers result in higher microvoid density and worse passivation quality. In contrast, the deposition at higher hydrogen dilution rates (R  >  5) leads to a degradation in the film quality with very low hydrogen content and crystalline epitaxial growth at the a-Si/c-Si interface. Thus, the best material quality is obtained just below the onset of amorphous-to crystalline transition (R  =  3), which favours further improvement of the passivation during a post-deposition annealing. [ABSTRACT FROM AUTHOR]

Nanoimprint lithography is used to directly pattern the conjugated polymer semiconductor poly(3-hexylthiophene) (P3HT). We obtain trenches with aspect ratios up to 2 and feature sizes as small as 50 nm in this polymer. The application to organic solar cells is shown by creating an interpenetrated donor-acceptor interface, based on P3HT and N,N'-ditridecyl-3,4,9,10-perylenetetracarboxylic diimide (PTCDI-C13), deposited from the vapor phase to reduce shadow effects. A planarizing layer of spin-coated zinc oxide (ZnO) nanoparticles is used to reduce the roughness of the layer stack. The response of the photovoltaic devices follows the increased interface area, up to a 2.5-fold enhancement. [ABSTRACT FROM AUTHOR]

This study presents a comprehensive evaluation of Copper Indium Gallium Selenide (CIGS) solar technology, benchmarked against crystalline silicon (c-Si) PERC PV technology. Utilizing a newly developed energy yield model, we analyzed the performance of CIGS in various environmental scenarios, emphasizing its behavior in low-light conditions and under different temperature regimes. The model demonstrated high accuracy with improved error metrics of normalized mean bias error (nMBE) ~ 1% and normalized root mean square error (nRMSE) of  ~ 8%-20% in simulating rack mounted setup and integrated PV systems. Key findings reveal that the CIGS technology, while slightly underperforming in integrated, low-irradiance setups, shows comparable or superior performance to c-Si PERC technology in high-irradiance and high-temperature conditions. A significant focus of the study was on the low-light performance of CIGS, where it exhibited notable voltage losses. Our research highlights the importance of reducing the diode ideality factor for enhancing CIGS power conversion efficiency, particularly In low-light conditions. These insights provide a pathway for future research and technological improvements, emphasizing defect engineering, passivation strategies to advance the understanding and application of the CIGS technology., Competing Interests: Declarations. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)

The metal halide perovskite absorbers are prone to surface defects, which severely limit the power conversion efficiencies (PCEs) and the operational stability of the perovskite solar cells (PSCs). Herein, trace amounts of bithiophene propylammonium iodide (bi-TPAI) are applied to modulate the surface properties of the gas-quenched perovskite. It is found that the bi-TPAI surface treatment has negligible impact on the perovskite morphology, but it can induce a defect passivation effect and facilitate the charge carrier extraction, contributing to the gain in the open-circuit voltage ( V oc ) and fill factor. As a result, the PCE of the gas-quenched sputtered NiO x -based inverted PSCs is enhanced from the initial 20.0% to 22.0%. Most importantly, the bi-TPAI treatment can largely alleviate or even eliminate the burn-in process during the maximum power point tracking measurement, improving the operational stability of the devices.

Volatile A-cation halide (AX) additives such as formamidinium chloride and methylammonium chloride have been widely employed for high-efficiency perovskite solar cells (PSCs). However, it remains unstudied how they influence the perovskite film stoichiometry and the solar cell performance and operational stability. Hereby, our work shows that over annealing of formamidinium chloride-containing perovskite films leads to a Pb-rich surface, resulting in a high initial efficiency, which however decays during maximum power point tracking (MPPT). On the contrary, perovskite films obtained by a shorter annealing time at the same temperature provide good stability during MPPT but a lower initial efficiency. Thus, we deduce that an optimal annealing is vital for both high efficiency and operational stability, which is then confirmed in the case where methylammonium chloride additive is used. With optimized perovskite annealing conditions, we demonstrate efficient and stable p-i-n PSCs that show a best power conversion efficiency of 20.7% and remain 90% of the initial performance after a 200 h MPPT at 60 °C under simulated 1 sun illumination with high UV content. Our work presents a comprehensive understanding on how volatile AX impacts perovskite film stoichiometry and its correlation to the device performance and operational stability, providing a new guideline for fabricating high-efficiency and operationally stable PSCs.

Passivating contacts consisting of heavily doped polycrystalline silicon (poly-Si) and ultrathin interfacial silicon oxide (SiO x ) films enable the fabrication of high-efficiency Si solar cells. The electrical properties and working mechanism of such poly-Si passivating contacts depend on the distribution of dopants at their interface with the underlying Si substrate of solar cells. Therefore, this distribution, particularly in the vicinity of pinholes in the SiO x film, is investigated in this work. Technology computer-aided design (TCAD) simulations were performed to study the diffusion of dopants, both phosphorus (P) and boron (B), from the poly-Si film into the Si substrate during the annealing process typically applied to poly-Si passivating contacts. The simulated 2D doping profiles indicate enhanced diffusion under pinholes, yielding deeper semicircular regions of increased doping compared to regions far removed from the pinholes. Such regions with locally enhanced doping were also experimentally demonstrated using high-resolution (5-10 nm/pixel) scanning spreading resistance microscopy (SSRM) for the first time. The SSRM measurements were performed on a variety of poly-Si passivating contacts, fabricated using different approaches by multiple research institutes, and the regions of doping enhancement were detected on samples where the presence of pinholes had been reported in the related literature. These findings can contribute to a better understanding, more accurate modeling, and optimization of poly-Si passivating contacts, which are increasingly being introduced in the mass production of Si solar cells.

To guarantee a long lifetime of perovskite-based photovoltaics, the selected materials need to survive relatively high-temperature stress during the solar cell operation. Highly efficient n-i-p perovskite solar cells (PSCs) often degrade at high operational temperatures due to morphological instability of the hole transport material 2,2',7,7'-tetrakis ( N , N -di- p -methoxyphenyl-amine)9,9'-spirobifluorene (Spiro-OMeTAD). We discovered that the detrimental large-domain spiro-OMeTAD crystallization is caused by the simultaneous presence of tert -butylpyridine ( t BP) additive and gold (Au) as a capping layer. Based on this discovery and our understanding, we demonstrated facile strategies that successfully stabilize the amorphous phase of spiro-OMeTAD film. As a result, the thermal stability of n-i-p PSCs is largely improved. After the spiro-OMeTAD films in the PSCs were stressed for 1032 h at 85 °C in the dark in nitrogen environment, reference PSCs retained only 22% of their initial average power conversion efficiency (PCE), while the best target PSCs retained 85% relative average PCE. Our work suggests facile ways to realize efficient and thermally stable spiro-OMeTAD containing n-i-p PSCs.

Hybrid metal halide perovskites have emerged as a potential photovoltaic material for low-cost thin film solar cells due to their excellent optoelectronic properties. However, high efficiencies obtained with lab-scale cells are difficult to replicate in large modules. The upscaling process requires careful optimization of multiple steps, such as laser scribing, which divides a module into serially connected cells using a pulsed laser beam. In this work, we characterize the effect of laser scribing on the perovskite layer adjacent to a P3 scribe line using analytical scanning and cross-sectional transmission electron microscopy techniques. We demonstrate that lateral flow of residual thermal energy from picosecond laser pulses decomposes the perovskite layer over extended length scales. We propose that the exact nature of the change in perovskite composition is determined by the presence of preexisting PbI 2 grains and hence by the original perovskite formation reaction. Furthermore, we show that along the P3 lines, the indium tin oxide contact is also damaged by high-fluence pulses. Our results provide a deeper understanding on the interaction between laser pulses and perovskite solar modules, highlighting the need to minimize material damage by careful tuning of both laser parameters and the device fabrication procedure.

For advanced optical analysis and optimization of solar cell structures with multi-scale interface textures, we applied a coupled modelling approach (CMA), where we couple the rigorous coupled wave analysis method with ray tracing and transfer matrix method. Coupling of the methods enables accurate optical analysis of solar cells made of thin coherent and thick incoherent layers and includes combinations of nano- and micro-scale textures at various positions in the structure. The approach is experimentally validated on standalone single- and both-side textured crystalline silicon wafers, as well as on complete silicon heterojunction (Si HJ) solar cell structures. Using CMA, fully encapsulated bifacial Si HJ solar cells are optically simulated first by applying single- and both-side illumination, and the effects of introducing nano inverted pyramids and random micro-pyramids at front and/or rear interfaces are analyzed. Secondly, an external light management foil with a three-sided pyramidal micro-texture is applied in simulations to the front and/or rear encapsulation glass, and the related improvements are quantified. For the optimal combination of internal textures in the analyzed structure (random micro-pyramids at the front and nano inverted pyramids at the back) and the use of the light management foil on both sides of the device, a 5.6% gain in the short-circuit current is predicted, compared to the reference case with no light management foil and with random micro-pyramids applied to the front and rear internal interfaces.

Background: Knee osteoarthritis ( k OA) is a common chronic disease that induces changes in redox status and inflammatory biomarkers, cell death, and motor impairment. Aerobic training can be a non-pharmacological alternative to prevent the progression of the disease., Objective: To evaluate the effects of an 8 weeks moderate-intensity treadmill aerobic training program on redox status and inflammatory biomarkers and motor performance in k OA-like changes induced by monosodium iodoacetate (MIA) in rats., Methods: Twenty-seven rats were randomly divided into three groups: SHAM; induced k OA (OA); and induced k OA + aerobic training (OAE). Motor performance was evaluated by the number of falls on rotarod test, the total time of displacement and the number of failures on a 100 cm footbridge. Data for cytokines and histology were investigated locally, whereas plasma was used for redox status biomarkers., Results: The OA group, compared to the SHAM group, increased 1.13 times the total time of displacement, 6.05 times the number of failures, 2.40 times the number of falls. There was also an increase in cytokine and in thiobarbituric acid reactive substances (TBARS) (IL1β: 5.55-fold, TNF: 2.84-fold, IL10: 1.27-fold, IL6: 1.50-fold, TBARS: 1.14-fold), and a reduction of 6.83% in the total antioxidant capacity (FRAP), and of 35% in the number of chondrocytes. The aerobic training improved the motor performance in all joint function tests matching to SHAM scores. Also, it reduced inflammatory biomarkers and TBARS level at values close to those of the SHAM group, with no change in FRAP level. The number of falls was explained by IL1β and TNF (58%), and the number of failures and the total time of displacement were also explained by TNF (29 and 21%, respectively)., Conclusion: All findings indicate the efficacy of moderate-intensity aerobic training to regulate inflammatory biomarkers associated with improved motor performance in induced k OA-like changes, thus preventing the loss of chondrocytes., (Copyright © 2019 Martins, Mendonça, Aguiar, Fonseca, Santos, Tossige-Gomes, Melo, Oliveira, Leite, Camargos, Ferreira, Coimbra, Poortmans, Oliveira, Silva, Domingues, Bernardo-Filho and Lacerda.)

With the realization of highly efficient perovskite solar cells, the long-term stability of these devices is the key challenge hindering their commercialization. In this work, we study the temperature-dependent stability of perovskite solar cells and develop a model capable of predicting the lifetime and energy yield of perovskite solar cells outdoors. This model results from the measurement of the kinetics governing the degradation of perovskite solar cells at elevated temperatures. The individual analysis of all key current-voltage parameters enables the prediction of device performance under thermal stress with high precision. An extrapolation of the device lifetime at various European locations based on historical weather data illustrates the relation between the laboratory data and real-world applications. Finally, the understanding of the degradation mechanisms affecting perovskite solar cells allows the definition and implementation of strategies to enhance the thermal stability of perovskite solar cells.

Fullerene-based molecules are the archetypical electron-accepting materials for organic photovoltaic devices. A detailed knowledge of the degradation mechanisms that occur in C60 layers will aid in the development of more stable organic solar cells. Here, the impact of storage in air on the optical and electrical properties of C60 is studied in thin films and in devices. Atmospheric exposure induces oxygen-trap states that are 0.19 eV below the LUMO of the fullerene C60. Moreover, oxygen causes a 4-fold decrease of the exciton lifetime in C60 layers, resulting in a 40% drop of short-circuit current from optimized planar heterojunction solar cells. The presence of oxygen-trap states increases the saturation current of the device, resulting in a 20% loss of open-circuit voltage. Design guidelines are outlined to improve air stability for fullerene-containing devices.

We report on the fabrication of disordered nanostructures by combining colloidal lithography and silicon etching. We show good control of the short-range ordered colloidal pattern for a wide range of bead sizes from 170 to 850 nm. The inter-particle spacing follows a Gaussian distribution with the average distance between two neighboring beads (center to center) being approximately twice their diameter, thus enabling the nanopatterning with dimensions relevant to the light wavelength scale. The disordered nanostructures result in a lower integrated reflectance (8.1%) than state-of-the-art random pyramid texturing (11.7%) when fabricated on 700 µm thick wafers. When integrated in a 1.1 µm thin crystalline silicon slab, the absorption is enhanced from 24.0% up to 64.3%. The broadening of resonant modes present for the disordered nanopattern offers a more broadband light confinement compared to a periodic nanopattern. Owing to its simplicity, versatility and the degrees of freedom it offers, this potentially low-cost bottom-up nanopatterning process opens perspectives towards the integration of advanced light-trapping schemes in thin solar cells.

The removal of secondary phases from the surface of the kesterite crystals is one of the major challenges to improve the performances of Cu2ZnSn(S,Se)4 (CZTSSe) thin film solar cells. In this contribution, the KCN/KOH chemical etching approach, originally developed for the removal of CuxSe phases in Cu(In,Ga)(S,Se)2 thin films, is applied to CZTSe absorbers exhibiting various chemical compositions. Two distinct electrical behaviors were observed on CZTSe/CdS solar cells after treatment: (i) the improvement of the fill factor (FF) after 30 s of etching for the CZTSe absorbers showing initially a distortion of the electrical characteristic; (ii) the progressive degradation of the FF after long treatment time for all Cu-poor CZTSe solar cell samples. The first effect can be attributed to the action of KCN on the absorber, that is found to clean the absorber free surface from most of the secondary phases surrounding the kesterite grains (e.g., Se0, CuxSe, SnSex, SnO2, Cu2SnSe3 phases, excepting the ZnSe-based phases). The second observation was identified as a consequence of the preferential etching of Se, Sn, and Zn from the CZTSe surface by the KOH solution, combined with the modification of the alkali content of the absorber. The formation of a Cu-rich shell at the absorber/buffer layer interface, leading to the increase of the recombination rate at the interface, and the increase in the doping of the absorber layer after etching are found to be at the origin of the deterioration of the FF of the solar cells.

Sintered porous silicon is a well-known seed for homo-epitaxy that enables fabricating transferrable monocrystalline foils. The crystalline quality of these foils depends on the surface roughness and the strain of this porous seed, which should both be minimized. In order to provide guidelines for an optimum foil growth, we present a systematic investigation of the impact of the thickness of this seed and of its sintering time prior to epitaxial growth on strain and surface roughness. Strain and surface roughness were monitored in monolayers and double layers with different porosities as a function of seed thickness and of sintering time by high-resolution X-ray diffraction and profilometry, respectively. Unexpectedly, we found that strain in double and monolayers evolves in opposite ways with respect to layer thickness. This suggests that an interaction between layers in multiple stacks is to be considered. We also found that if higher seed thickness and longer annealing time are to be preferred to minimize the strain in double layers, the opposite is required to achieve smoother layers. The impact of these two parameters may be explained by considering the morphological evolution of the pores upon sintering and, in particular, the disappearance of interconnections between the porous seed and the bulk as well as the enlargement of pores near the surface. An optimum epitaxial growth hence calls for a trade-off in seed thickness and annealing time, between minimum-strained layers and rougher surfaces., Pacs Codes: 81.40.-z Treatment of materials and its effects on microstructure, nanostructure, and properties; 81.05.Rm Porous materials; granular materials; 82.80.Ej X-ray, Mössbauer and other γ-ray spectroscopic analysis methods.

Excessive visceral adipose tissue appears to trigger a cascade of metabolic disturbances that seem to coexist with ectopic fat storage in muscle, liver, heart and the ß-cell. Therefore, the reduction of visceral adipose tissue potentially plays a pivotal role in the treatment of the metabolic syndrome. The purpose of this systematic review and meta-analysis is to describe the overall effect of exercise on visceral adipose tissue and to provide an overview of the effect of different exercise regimes, without caloric restriction, on visceral adipose tissue in obese persons. A systematic literature search was performed according to the PRISMA statement for reporting systematic reviews and meta-analyses. The initial search resulted in 87 articles after removing duplicates. After screening on title, abstract and full-text 15 articles (totalling 852 subjects) fulfilled the a priori inclusion criteria. The quality of each eligible study was assessed in duplicate with "The Critical Review Form for Quantitative Studies". Using random-effects weights, the standardized mean difference (Hedge's g) of the change in visceral adipose tissue was -0.497 with a 95% confidence interval of -0.655 to -0.340. The Z-value was -6.183 and the p-value (two tailed) was <0.001. A subgroup analysis was performed based on gender, type of training and intensity. Aerobic training of moderate or high intensity has the highest potential to reduce visceral adipose tissue in overweight males and females. These results suggest that an aerobic exercise program, without hypocaloric diet, can show beneficial effects to reduce visceral adipose tissue with more than 30 cm(2) (on CT analysis) in women and more than 40 cm(2) in men, even after 12 weeks.

: Because of its optical and electrical properties, large surfaces, and compatibility with standard silicon processes, porous silicon is a very interesting material in photovoltaic and microelectromechanical systems technology. In some applications, porous silicon is annealed at high temperature and, consequently, the cylindrical pores that are generated by anodization or stain etching reorganize into randomly distributed closed sphere-like pores. Although the design of devices which involve this material needs an accurate evaluation of its mechanical properties, only few researchers have studied the mechanical properties of porous silicon, and no data are nowadays available on the mechanical properties of sintered porous silicon. In this work we propose a finite element model to estimate the mechanical properties of sintered meso-porous silicon. The model has been employed to study the dependence of the Young's modulus and the shear modulus (upper and lower bounds) on the porosity for porosities between 0% to 40%. Interpolation functions for the Young's modulus and shear modulus have been obtained, and the results show good agreement with the data reported for other porous media. A Monte Carlo simulation has also been employed to study the effect of the actual microstructure on the mechanical properties.

We describe a high sensitivity measurement setup for the determination of recombination parameters in semiconductors at low levels of carrier injection. The setup is based on a lock-in amplifier and on a commercially available contactless conductivity detector. The information on recombination is extracted through the analysis, assuming quasi-steady-state conditions, of the low frequency, sinusoidally modulated photoconductivity signal induced by the illumination of a 950 nm light emitting diode array. Experimental results show a substantial increase in sensitivity with respect to traditional transient or quasi-steady-state techniques based on the same detection principle. The sensitivity bonus can be exploited for the extension of the carrier injection range for which effective recombination lifetime is measurable, both in the case of p-type and n-type wafers.

1. To address the question of whether endotoxaemia could be involved in the inflammatory response induced by long-term strenuous exercise, 18 male marathon runners [mean age 41 +/- 2 (SEM) years] were studied. Their performance in the marathon ranged from 2 h 46 min to 4 h 42 min. 2. Four venous blood samples were drawn: at rest, just before the race (baseline); within 15 min following the completion of the marathon; after 1 h of recovery; and the morning after the race. 3. The following humoral markers of the inflammatory response to exercise were measured: polymorphonuclear myeloperoxidase (MPO), anaphylatoxin C5a (C5a), tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6). Plasma endotoxin was measured by a sensitive and rapid chromogenic Limulus assay. All inflammatory markers were significantly increased (P < 0.001) after the race, reaching in most cases peak values in the first blood sample drawn following the completion of the marathon [MPO, 298 +/- 19 ng/ml (SEM); C5a, 1.45 +/- 0.32 ng/ml; TNF-alpha, 20 +/- 3 pg/ml; IL-6, 88 +/- 13 pg/ml] when compared with baseline [MPO, 146 +/- 16 ng/ml (SEM); C5a, 0.27 +/- 0.2 ng/ml; TNF-alpha, 12 +/- 1.5 pg/ml: IL-6, 1.0 +/- 0.5 pg/ml]. Traces of plasma endotoxin (ranging from 5 to 13 pg/ml, with one exceptionally high value of 72 pg/ml measured in one runner) were detected in seven subjects within the first hour of recovery. An ELISA method was used to determine the endogenous IgG antibodies toward a range of Gram-negative bacterial lipopolysaccharides (LPSs) of different sizes and structures. A transient decrease in certain anti-LPS activities, mainly against rough LPS, occurred in most cases in the first blood sample drawn after the race. There was no correlation between the magnitude of the inflammatory response to exercise, as assessed by the increase in blood levels of humoral markers of inflammation, and the changes in circulating endotoxin levels of anti-LPS IgG activity following the race. 4. From these results, we conclude that the mild, transient endotoxaemia detected in some of our subjects does not play a major role in the observed inflammatory response to a marathon competition.

The triad of insulin, diet and exercise has been the basis for treatment of diabetes for several decades. However, the choice of sporting activities for young diabetics requires an understanding of: a) the energy metabolism and the adaptation to physical activity in the healthy; b) the metabolic adaptation during physical activity in the diabetic child; and c) the practical recommendations concerning diet and insulin that have to be learned by the children themselves. The healthy child utilises immediately available substrates, such as ATP and creatine phosphate in much the same fashion as the adult. However, the capacity for anaerobic degradation of glycogen and glucose seems limited in the muscles of children relative to that of adults. Consequently, the adaptation to resistance exercise should be undertaken with prudence in children and adolescents. The release of insulin tends to decrease during effort. Diverse hypotheses have been proposed to explain this phenomenon. However a low concentration of insulin is required: insulin is said to play a "permissive" role. In diabetic children, an adequate insulin therapy is required to allow the full benefit of muscular activity on glucose assimilation and to reach the same level of physical performance as the non-diabetic. In the case of insufficient metabolic control, exercise can provoke severe hypoglycaemic episodes, even after muscle activity has ceased, or increase glucose levels and lead to ketoacidosis. Regular physical training induces a reduction in postexercise proteinuria measured in diabetic adolescents but its role in metabolic control remains controversial.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in platelet aggregability during maximal bicycle ergometry were studied in healthy untrained subjects. Ex vivo platelet aggregation in response to ADP and collagen was measured in whole blood by impedance aggregometry or by direct electronic counting in an Ultra-Flo 100 platelet counter. This last method revealed that the platelet aggregation induced by low concentration of ADP (0.5 - 1.0 microM) was significantly enhanced during exercise. The plasma level of beta-thromboglobulin and the urinary excretion of 2,3--dinor-6-keto prostaglandin F1 alpha were also increased. These data indicate that an intense physical exercise enhances the aggregability of human platelets and induces a compensatory increase in prostacyclin biosynthesis.

In six insulin deprived adolescent diabetics, the influence of muscular effort equal to 50% of the VO2 max on the coefficient of glucose assimilation was evaluated. During an IVTT the coefficient of glucose assimilation at rest was (0.59). 10(-2) +/- 0.14 and it did not increase during physical activity. A minimal concentration of insulin is apparently indispensable to increase glucose utilisation during muscular effort. At higher concentrations other factors probably intervene to enhance glucose assimilation.

The influence of chronic therapy with nifedipine on the pharmacokinetics of propranolol 80 mg twice daily, metoprolol 100 mg twice daily and atenolol 100 mg once daily was investigated in eight healthy volunteers. Nifedipine 10 mg three times daily did not affect the pharmacokinetics of metoprolol and atenolol whereas nifedipine shortened the time to peak plasma concentration for propranolol by about 1 h. Propranolol, metoprolol and atenolol provoked comparable decreases in heart rate measured at rest and during exercise. The beta-adrenoceptor blocking properties of propranolol, metoprolol and atenolol were not affected by concomitant therapy with nifedipine. The present study did not show significant pharmacokinetic and pharmacodynamic interactions between nifedipine and lipophilic beta-adrenoceptor blockers.

Four rabbit antibodies have been prepared, which are specifically directed against alpha-lactalbumins from different sources; namely human, cow, goat and sheep milk. Each of these antibodies was tested for its ability to react with, separately, each of the four proteins. The immunological reactions were assessed by means of different techniques: double immunodiffusion in agar gel as well as affinity chromatography of antibodies, using antigens covalently bound to an insoluble matrix. In each case, the strongest reaction was observed between homologous antibody and (matrix-bound) antigen; heterologous antigens were, however, also capable of cross-reaction. Whereas no cross-reaction between human alpha-lactalbumin and antibodies against the bovine protein could be evidenced by immunodiffusion, the occurrence of soluble complexes has been disclosed by means of a gel filtration technique.

The triad of insulin, diet and exercise has been the basis for treatment of diabetes for several decades. However, the choice of sporting activities for young diabetics requires an understanding of: (a) the energy metabolism and the adaptation to physical activity in the healthy; (b) the metabolic adaptation during physical activity in the diabetic child; and (c) the practical recommendations concerning diet and insulin that have to be learned by the children themselves. The healthy child utilises immediately available substrates, such as ATP and creatine phosphate in much the same fashion as the adult. However, the capacity for anaerobic degradation of glycogen and glucose seems limited in the muscles of children relative to that of adults. Consequently, the adaptation to resistance exercise should be undertaken with prudence in children and adolescents. In diabetic children, an adequate insulin therapy is required to allow the full benefit of muscular activity on glucose assimilation and to reach the same level of physical performance as the non-diabetic. In the case of insufficient metabolic control, exercise can provoke severe hypoglycaemic episodes, even after muscle activity has ceased, or increase glucose levels and lead to ketoacidosis. Regular physical training induces a reduction in postexercise proteinuria measured in diabetic adolescents but its role in metabolic control remains controversial. If a diabetic child or adolescent follows individual recommendations concerning diet and insulin, he or she can perform physical activity much the same as a young non-diabetic. These recommendations include: (a) self-measurement of blood glucose concentration before and after exercise; (b) ingestion of carbohydrates before, during, and after exercise; (c) reduction of the insulin dose during and immediately after exercise; and (d) not choosing an injection site involved with muscular work. The only prohibited sports are those which constitute a danger to the diabetic child by provoking an eventual hypoglycaemia. The best sports are those that require progressive physical effort and that are spread out over several hours.

Urinary total protein, albumin and beta2-microglobulin excretion during exercise on a bicycle ergometer was determined in a group of 7 adolescent male diabetics and in a comparable control group. There was no difference, neither in the diabetic group nor in the control group, in the excretion of these proteins under the provocative effect of physical exercise. These results suggest exercise may not always give a positive response and is not a discriminative function in reliable studies of renal function.

To determine whether protein excretion during exercise is an earlier sign of renal dysfunction in diabetic adolescents than the basal measurements, urinary creatinine, total proteins, albumin, and beta 2-microglobulin were studied before, immediately after, and 30 min after exercise until exhaustion on a bicycle ergometer in a group of 21 adolescent diabetic boys (Albustix negative) and in a comparable control group. Among the 21 diabetic subjects, 11 had an incipient retinopathy diagnosed by fluorescein angiography. Urinary output of creatinine was similar in diabetic and in nondiabetic groups, and did not vary during exercise. At rest, the urinary output of total proteins, albumin, and beta 2-microglobulin was significantly higher in diabetic subjects than in controls. These data suggest that the subclinical proteinuria of diabetes is of mixed origin, being both glomerular and tubular. An exercise test leading to exhaustion did not give any additional information other than the basal excretion. There was no difference between diabetic subjects with early retinal vascular changes and those free from all retinopathy.

In an effort to determine the synthetic capacity of human kidneys for serum proteins, pieces of both kidneys removed at operation prior to transplantation were placed in organ culture. Incubation with 14C labelled amino acids and subsequent radioimmunoelectrophoresis with antisera to all five classes of immunoglobulins showed synthesis of IgG by all 5 pairs of kidneys of IgA and IgE by 4, and of IgM by 2. None synthesized IgD. Radioimmunoelectrophoresis with specific antisera to 15 non-immunoglobulin proteins revealed synthesis of lactoferrin and uromucoid while several other serum proteins, such as alpha1 antitrypsin and alpha2 macroglobulin, known for their binding properties, showed apparent synthesis. No evidence for secretory component synthesis was seen despite positive immunofluorescent localization in the tubular cells. Further, Zn alpha2 and beta2GP I also showed positive immunofluorescence but negative synthesis. It seems possible that these latter proteins may not be synthesized by the tubular cells but rather may be actively excreted or reabsorbed by them.

In order to obtain information concerning the CPK turnover during exercise, we have elaborated a technique to measure its activity continuously in vivo. A colorimetric method has been adapted to total blood. CPK was measured continuously in 5 physically fit athletes exercised on an ergometric bicycle for 30 min. There was practically no increase in enzymatic activity. The starting level was very high, corresponding perhaps to a "permanent state of enzyme release"; the exercise was not hard enough because of the fitness of the athletes or the maximal increase did not occur immediately after the exercise.