Bridge percolation: electrical connectivity of discontinued conducting slabs by metallic nanowires

The properties of nanostructured networks of conductive materials have been extensively studied under the lens of percolation theory. In this work, we introduce a novel type of local percolation phenomenon used to investigate the conduction properties of a new hybrid material that combines sparse metallic nanowire networks and fractured conducting thin films on flexible substrates. This original concept could potentially lead to the design of a novel composite transparent conducting material. Using a complementary approach including formal analytical derivations, Monte Carlo simulations and electrical circuit representation for the modelling of bridged-percolating nanowire networks, we unveil the key relations between linear crack density, nanowire length and network areal mass density that ensure electrical percolation through the hybrid. The proposed theoretical model provides key insights into the conduction mechanism associated with the original concept of bridge percolation in random nanowire networks.

[First-line management of infertile couple. Guidelines for clinical practice of the French College of Obstetricians and Gynecologists 2022]

OBJECTIVE

To update the 2010 CNGOF clinical practice guidelines for the first-line management of infertile couples.

MATERIALS AND METHODS

Five major themes (first-line assessment of the infertile woman, first-line assessment of the infertile man, prevention of exposure to environmental factors, initial management using ovulation induction regimens, first-line reproductive surgery) were identified, enabling 28 questions to be formulated using the Patients, Intervention, Comparison, Outcome (PICO) format. Each question was addressed by a working group that had carried out a systematic review of the literature since 2010, and followed the Grading of Recommendations Assessment, Development and Evaluation (GRADE®) methodology to assess the quality of the scientific data on which the recommendations were based. These recommendations were then validated during a national review by 40 national experts.

RESULTS

The fertility work-up is recommended to be prescribed according to the woman's age: after one year of infertility before the age of 35 and after 6months after the age of 35. A couple's initial infertility work-up includes a single 3D ultrasound scan with antral follicle count, assessment of tubal permeability by hysterography or HyFOSy, anti-Mullerian hormone assay prior to assisted reproduction, and vaginal swabbing for vaginosis. If the 3D ultrasound is normal, hysterosonography and diagnostic hysteroscopy are not recommended as first-line procedures. Chlamydia trachomatis serology does not have the necessary performance to predict tubal patency. Post-coital testing is no longer recommended. In men, spermogram, spermocytogram and spermoculture are recommended as first-line tests. If the spermogram is normal, it is not recommended to check the spermogram. If the spermogram is abnormal, an examination by an andrologist, an ultrasound scan of the testicles and hormonal test are recommended. Based on the data in the literature, we are unable to recommend a BMI threshold for women that would contraindicate medical management of infertility. A well-balanced Mediterranean-style diet, physical activity and the cessation of smoking and cannabis are recommended for infertile couples. For fertility concern, it is recommended to limit alcohol consumption to less than 5 glasses a week. If the infertility work-up reveals no abnormalities, ovulation induction is not recommended for normo-ovulatory women. If intrauterine insemination is indicated based on an abnormal infertility work-up, gonadotropin stimulation and ovulation monitoring are recommended to avoid multiple pregnancies. If the infertility work-up reveals no abnormality, laparoscopy is probably recommended before the age of 30 to increase natural pregnancy rates. In the case of hydrosalpinx, surgical management is recommended prior to ART, with either salpingotomy or salpingectomy depending on the tubal score. It is recommended to operate on polyps>10mm, myomas 0, 1, 2 and synechiae prior to ART. The data in the literature do not allow us to systematically recommend asymptomatic uterine septa and isthmoceles as first-line surgery.

CONCLUSION

Based on strong agreement between experts, we have been able to formulate updated recommendations in 28 areas concerning the initial management of infertile couples.

Is there a role for a handheld gamma camera (TReCam) in the SNOLL breast cancer procedure?

BACKGROUND

Sentinel node and occult lesion localization (SNOLL) calls for a combination of two specific procedures: intraoperative detection of sentinel lymph node (SLN) and radio-guided occult lesion localization (ROLL). The safety and benefits of radio-guided localization in the surgical treatment of non-palpable breast cancer have been confirmed. The aim of this study was to evaluate the potential role for an intra-operative handheld tumor resection gamma camera (TReCam) in SNOLL procedures.

METHODS

Fifteen patients were enrolled. The SNOLL procedure was performed in all patients with conventional lymphoscintigraphy (LS). TReCam was used to obtain nuclear imaging in the operating theater. Concordance between LS and TReCam images, duration of use and assessment of difficulties in data acquisition with TReCam were reported.

RESULTS

Concordance for tumor localization between single-detector gamma probe and TReCam was excellent (15/15). The number of radioactive SLNs visualized between LS and TReCam was equivalent in 53.3% of cases (8/15). TReCam was considered to be very easy-to-use (12/15) or easy-to-use (3/15). Average duration of acquisition with TReCam was 4 minutes and 45 seconds for the SLN procedure, and 2 minutes and 10 seconds for lumpectomy.

CONCLUSIONS

This study suggests that TReCam is easy-to-use and does not increase operative time. Its exact role in radio-guided surgery needs to be clearly defined in a larger study. However, its usefulness and benefits in radio-guided breast surgery seem to be promising.

[Role of health volunteers for patients with amyotrophic lateral sclerosis and their family]

In ALS Centers, the patient receives coordinated care from Health Volunteers and the medical team including specialized physicians, therapists and social workers. There are two types of volunteers: those who assist the patient in hospital, the Medical Volunteers (MV), and those who make home visits, the Home Volunteers (HV). Both are recruited and trained by the ARS and have a single motivation: help the patient's; they are emotionally and morally fully qualified to accomplish their task in accordance with the rules that have been set by the Association. The ALS patient is seen for the first time by the Medical Volunteer at the ALS Center, immediately after his or her disease has been diagnosed by the clinic's director. The MV takes the initiative for the dialogue, which he/she leads gently and tactfully. The discussion is aimed at gathering useful information to be put in the document: "Connaissance du malade" (knowledge of the patient), working out the patient's primary concerns and assessing the carer's commitment, in a friendly atmosphere. Finally the volunteer gives the guidebook, "Livret d'accueil" to the patient. After the conversation, the MV decides which confidential pieces of information are to be passed on to the medical staff with a view to sorting out problems; information is then set the HV who will provide follow up care for this patient. Long-term care management of ALS patients is achieved through three regular monthly appointments at the ALS Center. With the help of the document "Connaissance du malade" the MV keeps better in touch with the patient using the feedback from the HV about what has been going on in the interval between the two visits to the ALS Center. This collaboration enables appropriate follow up care for the patients with clearly-defined objectives: dealing with the patient's anxiety, understanding his/her position at the present time, his/her daily routine and needs, comforting, checking compliance with treatment, counselling and supporting the family, answering delicate questions. Thus, the Health Volunteer's mission contributes meaningfully to medical treatment. This approach likely helps the person affected by ALS to regain the initially deteriorated sense of belonging to the social body.

Effects of zinc supplementation on blood rheology during exercise

We previously reported a higher blood viscosity at corrected hematocrit (45%) (explained by a higher value of erythrocyte rigidity) in football players with low serum zinc (Zn) and thus presumably Zn deficiency; subjects with low serum zinc had also an impairment in performance. This interventional study was undertaken in order to assess the effects of zinc supplementation (compared to placebo) on blood rheology and performance either at rest or during exercise. Ten male healthy volunteers (age: 26+/-1.3 yr; weight 67.9+/-2.24 kg; height 177+/-3 cm) received at random order either zinc (20 mg/day) and placebo, according to a double blind cross-over procedure, during seven days. In each case on the eighth day they performed a 25 min submaximal exercise-test. At rest blood viscosity at corrected hematocrit 45% (gamma = 1000 s(-1)) was lower after Zn (3.56+/-0.14 vs. 4.13+/-0.16 mPa.s, p = 0.009), explained by a lower RBC rigidity index 'k' according to Quemada's equation (1.65+/-0.07 vs. 1.84+/-0.08, p = 0.03). Hematocrit and plasma viscosity were unchanged, but RBC aggregation was decreased (laser retrodiffusion-derived aggregation time 'Ta' 3.52+/-0.51 vs. 2.75+/-0.59, p = 0.02). The increase in blood viscosity during exercise is lower after Zn than placebo. Blood viscosity at corrected hematocrit 45% remains unchanged during exercise after Zn, yet it increases after placebo. RBC rigidity index 'k' remains lower during exercise after Zn. The rating of perceived exertion (Borg's scale) at the 20th minute of exercise is lower after zinc (5.6+/-0.4 vs. 6.6+/-0.4, p = 0.008). This study confirms that Zn improves erythrocyte deformability, decreases the exercise-induced acute increase in blood viscosity, and improves exercise tolerance. Since Zn deficiencies are not unfrequent in sportsmen, these findings may be potentially relevant to sports nutrition.

Serum zinc and blood rheology in sportsmen (football players)

We aimed at investigating relationships between zinc status, blood rheology and blood glucose during exercise. Twenty-one professional football players underwent a triangular maximal exercise test on cycloergometer, with progressively increasing work loads until VO2max. On the whole these subjects had a low serum zinc because nine of them had a hypozincemia (0.54 +/- 0.01 mg/l) which suggested a zinc deficiency. Subjects with low serum zinc were able to perform a lower power output (123 +/- 8.71 vs. 166.27 +/- 14.84 watts, p = 0.029) and exhibited a higher increase in blood lactate during exercise (7.51 +/- 0.81 vs. 5.57 +/- 0.33 mmol/l, p = 0.024) resulting in a lower 2 mmol lactate threshold (44.7 +/- 3.9% vs. 58.9 +/- 4.8% of maximal power output, p = 0.04). They were less able to maintain their plasma glucose and exhibited a tendency towards hypoglycemia (p = 0.0153). Hypozincemia was associated with a higher viscometric RBC rigidity index (p = 0.0009), and this index was negatively correlated to serum zinc (r = -0.68, p = 0.7 x 10(-3)). Blood viscosity at high shear rate (MT90 viscosimeter) corrected for hematocrit (45%) remained higher during exercise in these hypozincemic subjects (p = 0.003). This study suggests that zinc status may influence blood rheology during exercise, either by its direct action on RBC flexibility (demonstrated in vitro) or by its effect on lactate accumulation which may in turn modify erythrocyte fexibility.

Effects of zamic as a means for zinc supplementation in growing children

We investigated the effects of zinc supplementation in case of moderate growth retardation in which GH treatment could not be used. Zamic (ZA, an association containing arginine, L-methionine, and zinc; from Aguettant pharmaceuticals) was compared with arginine aspartate (AA) (5 g) in a crossover randomized trial (6 mo of each treatment at random order over 1 yr). We present preliminary results of 24 children who completed the study (3 girls, 21 boys, age 9-13 yr). Subjects had to be prepubertal, with no GH deficiency diagnosed. In 15 subjects growth velocity was lower than 5 mm/mo: In this case ZA improved growth velocity (rising from 3.105 +/- 0.229 to 5.4 +/- 0.69 mm/mo p < 0.01), whereas the effect of AA was not significant. The increase in growth velocity was higher with ZA (+2.44 +/- 0.657 mm/mo) than AA (+0.438 +/- 0.450 mm/mo) p < 0.05. These results suggest that ZA is more efficient than AA, consistent with the hypothesis that zinc needs are increased in those children in this period of life.

Serum zinc in highly trained adolescent gymnasts

Serum zinc was measured in 20 adolescent gymnasts (9 boys, 11 girls, age 12-15 yr) explored for detecting possible adverse effects of intense training on pubertal maturation and growth. They had low serum zinc (0.599 +/- 0.026 mg/L) when compared to matched control sedentary children (n = 118 mean 0.81 +/- 0.014 p < 0.001). Girls had lower zinc than boys (0.557 +/- 0.023 vs 0.651 +/- 0.044 p < 0.001). Zinc was correlated to isometric adductor strength (r = 0.468 p < 0.05). Children with serum zinc < 0.6 mg/L had lower insulin-like growth factor binding protein 3 than others (2.326 +/- 0.264 vs 2.699 +/- 0.12 p < 0.01). Thus, zinc is lowered in trained adolescent gymnasts and even lower in females. This reduction could play some role in abnormalities of puberty, growth, or muscular performance.

In vitro influence of zinc and magnesium on the deformability of red blood cells artificially hardened by heating

Trace elements have been shown to improve red blood cell (RBC) deformability: zinc in sickle cell disease and magnesium in an in vitro model of chemically rigidified erythrocytes. In this study, we investigated the effect and the influence of incubation time of zinc or magnesium on an in vitro model of rigidified RBCs by heating. Erythrocyte rigidity was determined by viscosimetry at high shear rate by a falling ball viscosimeter MT 90. In the first part of the study, six normal volunteers participated. Viscosimetry was performed on native blood before and after heating the sample for 10 min at 50 degrees C. Therefore, increasing concentrations of zinc gluconate (final concentration: 0.5-4 g/L) or isotonic NaCl as control medium were added to the sample. Heating induced a twofold increase in all indices of RBC rigidity (p < 0.05). At all these concentrations of zinc, a highly significant, dose-related fluidifying effect was observed (40-70%): this effect was immediately obtained and did not change over 60 min. Even at the highest concentration, recovery was not complete. In the second part of the study, we studied magnesium's effects on blood. In a first protocol, whole blood was rigidified by heating at 56 degrees C for 10 min, and the correcting effect of 5 min of incubation at 37 degrees C of RBCs in 150 mmol/L NaCl, MgSO4, magnesium acetate, and magnesium gluconate was investigated. In a second protocol, the same incubation with NaCl and magnesium salts was made on blood that had not been previously heated.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of oral zinc gluconate on glucose effectiveness and insulin sensitivity in humans

Zinc improves both insulin secretion and insulin sensitivity, and exerts insulin-like effects. We investigated its acute effects on the parameters of glucose assimilation determined with the minimal model technique from frequent sampling intravenous glucose tolerance test (FSIVGTT) in seven healthy volunteers. FSIVGTTs (0.5 g/kg of glucose, followed by 2 U insulin i.v. injection at 19 min) were performed after the subjects had taken 20 mg zinc gluconate twice (the evening before and 30 min before the beginning of the test) or placebo pills (simple blind randomized protocol). Glucose assimilation was analyzed by calculating Kg (slope of the exponential decrease in glycemia), glucose effectiveness Sg (i.e., ability of glucose itself to increase its own disposal independent of insulin response), and SI (insulin sensitivity, i.e. the effect of increases in insulinemia on glucose disposal). The two latter parameters were calculated by fitting the experimental data with the two equations of Bergman's "minimal model." Zinc increased Kg (p < 0.05) and Sg (p < 0.05), whereas SI and insulin first-phase secretion did not significantly increase. This study suggests that zinc improves glucose assimilation, as evidenced by the increase in Kg, and that this improvement results mainly from an increase in glucose effectiveness (insulin-like effect), rather than an action on insulin response or insulin sensitivity.

Serum zinc and somatic growth in children with growth retardation

A possible role for zinc deficiency in some cases of growth retardation in southern France was investigated. Control values for zinc for 160 children (age = 12.5 +/- 2.4 yr) are 0.85 +/- 0.22 mg/L (mean +/- 2 SD). Twenty-five children with low serum zinc values (less than 0.63 mg/L) and 25 matched short children with normal serum zinc values (greater than 0.63 mg/L) were studied. Children in the two groups did not differ significantly in age, pubertal development, stature, and weight. For the 25 children whose serum values were low, we found significantly lower values for bone age delay, growth velocity in mm/month, as well as the ratio between calculated growth velocity and theoretical growth velocity for the bone age (so that zincemia was correlated to these parameters in the whole sample of 50 subjects). Nevertheless, no significant difference could be found between the two groups for serum somatomedin C, serum osteocalcin values, and GH responses to the GH stimulatory tests (exercise test, overnight sampling, insulin-induced hypoglycemia, arginine test). Therefore, low serum zinc is associated with a retardation in both somatic growth and pubertal maturation.

Urinary zinc and its relationships with microalbuminuria in type I diabetics

We investigated whether zincuria is associated with microalbuminuria in type I (insulin-dependent) diabetics (IDDM). In 169 IDDM, 215 overnight urine samples were collected for simultaneous assay of zinc and albumin. In 76 samples with excessive microalbuminuria (greater than 15 mg/L), zincuria was higher than in the 139 other samples (0.83 +/- 0.06 vs 0.58 +/- 0.03 mg/L p less than 0.001), though zincuria and microalbuminuria were not significantly correlated. An exercise provocation test was performed in 78 IDDM. Although microalbuminuria increased, zincuria did not change during the test. Another group of 83 IDDM underwent urinary zinc determination over a period of 1 h of recumbency. The 48 patients who had a zincuria higher than the mean + 2 SD of control values had higher microalbuminuria at rest (48 +/- 16 micrograms/min vs 12 +/- 2 p less than 0.01) and after exercise (111 +/- 33 vs 42 +/- 14 p less than 0.02) than the remaining 35 subjects. Both subgroups did not differ for zinc intake and zincemia. Thus, incipient nephropathy as detected by the measurement of microalbuminuria is associated with a highly significant increase in zinc excretion, which is not proportional to albumin leakage, nor is it amplified during exercise. Hyperzincuria is not explained by an increase in zinc intake and does not result in hypozincemia.

Discriminant carbohydrate components of human milk according to donor secretor types

Because of the variability of human milk carbohydrate composition, we determined the discriminant carbohydrate components of the milk of 18 mothers according to their ABH and Lewis secretor types during the first week of lactation. Comparative chromatograms revealed that the presence of neuraminyloligosaccharides is linked to the ABH secretor groups, and that the absence of oligosaccharides with Lea or Leb specificity is linked to the Lewis nonsecretor types. The study of carbohydrate composition according to donor secretor types consisted of measuring 16 variables from 69 samples. Analysis of variance showed significant differences between groups: high levels of N-acetylneuraminic acid and low levels of galactose distinguished ABH secretors from nonsecretors (p less than 0.001). In the ABH secretor groups, A and H secretors had higher N-acetylglucosamine contents than B and AB secretors (p less than 0.001) and lower galactose levels (p less than 0.001). The Lewis secretor groups were distinguished by significantly higher fucose levels (p less than 0.001). The ABH(+)Le(a-b-) group had higher lactose contents than the other groups (p less than 0.01).

Variations in oligosaccharides and lactose in human milk during the first week of lactation

Variations in oligosaccharides and lactose in human milk were studied in 15 mothers during the first week of lactation. The neuraminyloligosaccharides and heavy neutral oligosaccharides increased slightly from days 2 to 5 postpartum and appeared to decrease until day 7. The lacto-N-difucohexaoses, lacto-N-fucopentaoses, and lacto-N-tetraose increased until day 5 and then decreased. Lactodifucotetraose and the fucosidolactoses decreased substantially until day 5 (p less than 0.05) and appeared to stablize in the following days. Lactose increased until day 5 (p less than 0.05) and continued to increase thereafter. Lactose was negatively correlated with total oligosaccharides (p less than 0.10). The fluctuations observed in total oligosaccharides from days 2 to 5 postpartum and their subsequent stabilization and regular decrease during lactation confirm the hypothesis of Kulski and Hartmann that mammary secretion occurs in three periods: colostrum for the first 36 h postpartum, transitional milk from days 2 to 5 postpartum, and mature milk after day 5. The oligosaccharide variations we found corresponded to those of other milk constituents observed by other authors. The significance of the oligosaccharide variations is discussed.

[Determination of micro-quantities of serum lithium by atomic absorption spectrophotometry. Significance and applications]

The dilution of serum and the ionic components having an usual effect upon the lithium assay is examined about their influences in the determination of lithium microquantities. These are discussed according to the technique selected as well as the normal ionic variations that may be come across in serums. The method was applied to determination of serum lithium rate in a group of old subjects. The got lithium distribution is unsymmetrical at lower rates and no influence of age or sex was obvious.

Diurnal variations and within the feed in lactose and oligosaccharides of human milk

Variations of lactose and oligosaccharides in human milk were studied during the day and the feed, by dialysis, chromatography on Bio-gel P-2 column, paper chromatography, colorimetric analysis and gas chromatography. Progressive changes were found during the day, but not during the feed. A diurnal variation in milk lactose was seen, which was the inverse of the oligosaccharides. Significant negative correlations between lactose and oligosaccharides were seen in the afternoon and evening (p less than 0.05). The minimal mean value of lactose at 19.00 h is 58.64 +/- 5.28 g/l and the maximal mean values of oligosaccharides was 17.93 +/- 2.28 g/l. The data are discussed with regard to other milk constituents and to their possible physiological relevance.

Variations of lactose and oligosaccharides in milk from women of blood types secretor A or H, secretor Lewis, and secretor H/nonsecretor Lewis during the course of lactation

Variations of lactose and oligosaccharides in human milk were studied over a 3-month lactation period by dialysis, chromatography on Bio-gel P-2 column, paper chromatography, colorimetric analysis and gas chromatography. Milk samples were collected from donors of various blood and secretor types. An increase in the concentration of lactose was noted: 59.25 +/- 1.61 to 72.17 +/- 1.35 g/l for the group of secretor A secretor Lea Leb individuals, and from 62.25 +/- 1.35 to 73.15 +/- 3.45 g/l for the group of secretor H secretor Lea Leb individuals. A decrease in the concentration of oligosaccharides was also found: from 16.71 +/- 0.99 to 7.90 +/- 1.29 g/l and from 18.51 +/- 0.74 to 7.33 +/- 0.65 g/l, respectively, for these same groups. In secretor H nonsecretor Lewis individuals, the concentration of lactose increased from 67.97 +/- 3.09 to 77.42 +/- 1.88 g/l, and the concentration of oligosaccharides decreased from 13.27 +/- 0.40 to 3.47 +/- 0.33 g/l. Analysis of oligosaccharide composition by chromatography showed that variations are in relation to the secretor Lewis type. All oligosaccharides decreased equally throughout the lactation period, regardless of the blood group. The decrease was more rapid, however, in the nonsecretor Lewis individuals. In these individuals, the absence of certain oligosaccharides is not compensated by an overproduction of the other oligosaccharides present or by biosynthesis of structurally different oligosaccharides. The origin of these oligosaccharides is discussed.

[A simple hemolytic plate method for complement activity estimation (author's transl)]

The previous single radial haemolysis method is simplified for complement activity assay in human serums. The proceeding a "one point" test is described. This new technique is remarkable by its simplicity and rapidity. A study of the precision shows tha possibility of to make use of this simple "one point" hemolytic plate method.

[A study of the single radial haemolysis optimization for complement haemolytic activity assay (author's transl)]

The experimental conditions for single radial haemolysis are analysed in order to optimize the haemolytic plate method for the assay of human total complement. The amount of haemolytic antibody used for sensitization of red cells, the concentration of sensitized sheep erythrocytes, the thickness of agarose layer, and the diameters of wells all exercise an influence on the area of haemolysis. The effects of these parameters are investigated with a view to obtaining the clearest reading and greatest sensitivity of the haemolytic activity plate method, and at the same time verifying the validity of the assay and the precision of the human serum haemolytic titres. This work reports the optimal experimental requirements with regard to the factors studied for minimizing the sources of error in complement haemolytic plate assay.

[Titration of the hemolytic activity of human complement after radial diffusion]

The hemolytic activity of human complement is evaluated after diffusion in agarose containing sensitized erythrocytes. The results show a linear relation between hemolysis area and logarithm of concentration.