[Influence of disposable diaper dependence on emotional behavior and related factors of preschool-aged children].

Objective: To investigate the influence of disposable diaper dependence (DDD) on emotional behavior and related factors of preschool-aged children. Methods: A total of 3 000 preschool-aged children from 16 kindergartens in Zhengzhou of Henan Province from October 2019 to March 2020 were selected and their parents were investigated by using a basic information questionnaire (including usage of disposable diapers), Strengths and Difficulties Questionnaire (SDQ) and Children's Sleep Questionnaire (PSQ). The differences in baseline and clinical data were compared between the DDD children and normal children, and multiple linear regression models were used to analyze the factors associated with emotional behavior in DDD children. Results: A total of 3 000 questionnaires were distributed and 2 775 (92.50%) were valid. The children ranged in age from 3 to 5 years, including 1 438 boys (51.82%) and 1 337 girls (48.18%). There were 98 (3.53%) children in DDD group and 2 677 (96.47%) children in normal group. The proportion of children living in cities in the DDD group was 58.16%, significantly higher than that of 41.84% in the normal children group (P<0.001). The abnormal detection rate of various factors in SDQ in DDD children, from high to low, were hyperactivity (n=14, 14.29%), peer communication problems (n=12, 12.24%), prosocial behavior (n=11, 11.22%), emotional symptoms (n=10, 10.20%) and conduct problems (n=7, 7.14%). The detection rates of abnormal total difficulty scores in DDD group and normal children were 7.14% (7 cases) and 0.78% (21 cases), respectively, with statistically significant differences (P<0.001). The proportions of emotional symptoms and hyperactivity disorder in DDD group were higher than those in normal group, and the differences were statistically significant (P<0.05). The PSQ score of children in DDD group was 3.01±2.02 which was not significantly different from the PSQ score of the normal group (2.71±2.10, P=0.157). The multi-factor analysis showed that caregiver's education level (ß=-1.135,95%CI:-1.910 to -0.359), urinary incontinence (ß=2.222, 95%CI: 1.105-3.339), fecal incontinence (ß=3.833, 95%CI: 2.691-4.975), urinary and fecal incontinence (ß=5.522, 95%CI: 4.145-6.899), and recurrent urinary tract infections(ß=3.523,95%CI: 1.798-5.248)were the independent influencing factors of emotional behavioral problems in DDD children (P<0.05). Conclusions: Children with DDD are more likely to have emotional behavioral problems than normal children. Caregiver's education level, urinary incontinence and recurrent urinary tract infections were influencing factors of emotional behavioral problems in DDD children.

[Pay attention to lower urinary tract dysfunction and the clinical application of urodynamic studies in children].

Lower urinary tract dysfunction (LUTD) is the dysfunction of bladder and urethra during bladder filling and voiding phase. There are two general categories: neurogenic and non-neurogenic. It can cause upper urinary tract damage if left untreated. Urodynamic study (UDS) can objectively detect the function of detrusor and sphincter of urethra as well as predict the damage of LUTD to upper urinary tract. However, the development of UDS for children in China has not been popularized, which affects the accurate diagnosis and the treatment of LUTD. This article reviewed the importance of paying attention to LUTD and promoting the clinical application of UDS in children, so as to improve the diagnosis and treatment of LUTD in children.

[Risk factors of postoperative voiding dysfunction in children with congenital anorectal malformation].

This study analyzed the clinical data of children with anorectal malformation (ARM)who underwent surgery from 2006 to 2021, and explored the related factors of postoperative voiding dysfunction (VD).A total of 60 children including 51 males and 9 females, aged 4-15 years, were enrolled. During follow up, normal voiding function were found in 43 cases, VD in 17 cases. It was found that middle to high clinical classification (OR＝6.732, 95%CI:1.854-24.443), multiple surgeries (OR＝3.712, 95%CI:1.133-12.160), associated spinal deformity (OR＝3.297, 95%CI:1.029-10.566) and abnormal postoperative defecation (OR＝4.971, 95%CI:1.387-17.816) were the risk factors of VD after ARM (all P<0.05). Urodynamic study and early intervention should be carried out in children with VD after ARM surgery.

[Analysis of video-urodynamic and clinical features of non-neuropathic lower urinary tract dysfunction in children].

Objective: To analyze the video-urodynamic(VUDS) and clinical features of non-neuropathic lower urinary tract dysfunction (NNLUTD) in children. Methods: Children diagnosed with NNLUTD in the First Affiliated Hospital of Zhengzhou University from January 2016 to December 2020 were included. Children with neurological, rectal dysfunction and anatomical abnormalities were excluded. VUDS and urinalysis were performed in all children who were divided into 4 groups accordingly: normal group (Normal group), detrusor overactivity group(DO group), detrusor sphincter dyssynergia group (DSD group) and detrusor underactivity group (DU group). VUDS and clinical features, vesicoureteral reflux (VUR) and urinary tract infections (UTI) were analyzed. Results: A total of 173 children were included in this study, including 103 males and 70 females, aged (7.2±3.3) years. VUDS showed that 46 cases (26.6%) were in Normal group, 63 cases (36.4%) in DO group, 39 cases (22.5%) in DSD group and 25 cases (14.5%) in DU group. Compared with Normal group and DO group, the proportion of VUR in DSD group and DU group was significantly higher [18(46.2%) and 11(44.0%) vs 7(15.0%) and 14(22.2%), all P<0.05],and the proportion of male children was significantly higher than that of female children with VUR only in DO group [12(32.4%) vs 2(7.7%), P=0.020 ]; Compared with DO group, the proportion of UTI in DSD group and DU group was significantly higher [16(41.0%) and 12(48.0%) vs 12(19.0%), all P<0.05], and the proportion of female children was significantly higher than that of male children with UTI in normal group, DO group and DU group [9(45.0%) vs 4(15.4%), 8(30.8%) vs 4(10.8%)and 7(87.5%) vs 5(29.4%), all P<0.05]. The maximum detrusor pressure in DSD group was significantly higher than that in Normal group, DO group and DU group [(95±47) vs (43±18), (56±18) and (12±9)cmH2O, all P<0.05, 1 cmH2O=0.098 kPa).Compared with Normal group and DO group, post void residual in DSD group and DU group was significantly increased [(58±38) and (70±62) vs (8±8) and (8±7)ml, all P<0.05], and the proportion of lower bladder compliance was significantly increased [(15(38.5%) and 11(44%) vs 1(2.2%) and 10(15.9%), all P<0.05]. Compared with normal group, the maximum bladder capacity of DO, DSD and DU group were all significantly decreased [(178±61), (184±81) and (194±93) vs (256±92)ml, all P<0.05]. The proportion of urgency had significant difference in the four groups [13(28.3%) in Normal group, 41(65.1%) in DO group, 22(56.4%) in DSD group and 11(44.0%) in DU group, P=0.001], and the proportion of dysuria had significant difference too [5(10.9%) in Normal group, 18(28.6%) in DO group, 20(51.3%) in DSD group and 15(60.0%) in DU group, P<0.001]. Conclusions: Children with 4 different conditions of NNLUTD have distinct video-urodynamic features. The higher ratio of VUR and UTI in DSD and DU children may be associated with reduced bladder compliance and increased post void residual. VUDS is useful for the diagnosis and treatment of refractory children with NNLUTD.

[Evaluation of the efficacy of a new variable frequency stimulation sacral neuromodulation in the treatment of detrusor hyperactivity with impaired contractility].

A total of 16 detrusor hyperactivity with impaired contractility (DHIC) patients who received 12 weeks remote variable frequency stimulation (VFS) were enrolled at the First Affiliated Hospital of Zhengzhou University from September 2020 to February 2021. The voiding diary, symptom score scales and incidence of complications were completed and recorded at baseline, constant frequency stimulation (CFS) and VFS phases. Compared with the CFS phase, voiding times, urge incontinence times and daily catheterization volume were reduced; average voiding amount and functional bladder capacity increased; and the quality of life score and mental health questionnaire assessment were improved in the VFS phase(all P<0.05). In the end, among all 16 patients, there were 14 whose symptoms had improved, and there were no new complications such as pain or infection at the implantation site, electrode displacement, and electric shock sensation in the stimulation area. VFS-SNM can not only improve the DHIC patients' lower urinary tract symptoms during storage and urination period, but also improve the patients' quality of life and satisfaction of the therapy.

[Establishment and validation of a predictive model for neurogenic urinary tract injury in children].

Objective: To establish a predictive model for upper urinary tract damage in children with neurogenic bladder and verify its efficacy. Methods: From January 2011 to December 2021, 143 children with NB in the Children's Hospital of Chongqing Medical University and 84 children with NB in the First Affiliated Hospital of Zhengzhou University were selected as the research objects. The former is set as the training set and the latter is set as the validation set, and the general parameters of the two are compared. The independent risk factors of upper urinary tract damage in children with NB were screened out by Lasso regression, and multivariate logistic regression analysis and a nomogram prediction model was established. The models were validated internally and externally on the training set and validation set, respectively, and the area under the receiver operating curve (ROC) was used to verify the accuracy of the model. Results: A total of 227 children with NB were included in this study, including 121 males and 106 females, aged (10.2±3.8) years. There was no significant difference in other parameters except age between the training set and validation set (all P>0.05); Lasso regression and multivariate logistic regression analysis showed that detrusor leakage point pressure (DLPP) ≥ 40 cmH2O (OR=4.76, 95%CI: 2.01-11.26, 1 cmH2O=0.098 kPa), overactive bladder (OAB) (OR=3.08, 95%CI: 1.34-7.04), bladder compliance (BC)<20 ml/cm H2O (OR=3.65, 95%CI: 1.41-9.47), history of previous urinary tract infection (OR=2.73, 95%CI: 1.09-6.81), and abdominal pressure/other voiding patterns (OR=2.86, 95%CI: 1.20-6.82) were risk factors for upper urinary tract damage in children with NB (all P<0.05). The above parameters were used to establish a nomogram model of upper urinary tract damage in children with NB. The internal and external validation results show that the AUC values for the training and validation sets were 0.84 (95%CI: 0.77-0.91) and 0.86 (95%CI: 0.79-0.94), respectively. Conclusion: The prediction model of upper urinary tract damage in children with NB constructed in this study has high discrimination, accuracy and clinical applicability, which can help clinicians identify high-risk patients and make individualized treatment design for these patients.

[Evaluation of refractory monosymptomatic nocturnal enuresis with ambulatory urodynamics monitoring and conventional urodynamics].

Objective: To explore the clinical value of ambulatory urodynamics monitoring (AUM) in the diagnosis and treatment of children with refractory monosymptomatic nocturnal enuresis (RMNE) by comparing the urodynamic parameters of AUM with those of conventional urodynamics (CUD). Methods: A total of 40 children (22 males and 18 females) diagnosed with RMNE in the First Affiliated Hospital of Zhengzhou University from May 2017 to September 2019 were collected. They were aged 9-16 years, and their frequency of nocturnal bed-wetting was≥2 times per week. CUD and one sleep cycle AUM were performed, respectively. Then, the urodynamic parameters were recorded and analyzed. Results: Five of the 40 children dropped out of the study because of the poor compliance. The age of children with RMNE was(12.6±2.1)years old, the ratio of male to female was 19∶16, and the severity of enuresis (enuresis frequency) was(4.2±1.7) times per week. Compared to the CUD group, the bladder compliance (BC) [(28.4±7.7) ml/cmH2O vs (23.6±6.1) ml/cmH2O(1 cmH2O=0.098 kPa)] and maximum detrusor pressure (Pmax.det) [(44.6±9.1) cmH2O vs (36.8±8.3) cmH2O] in the AUM group were significantly higher (P<0.05). The maximum flow rate (Qmax) [(19.6±7.2) ml/s vs (20.9±5.4) ml/s] and post void residual (PVR) [(9.5±5.7) ml vs (10.9±5.3) ml] between the two groups showed no statistically significant differences (P>0.05). Detrusor overactivity (DO) was detected in 27 cases (77.1%) during AUM and in 16 cases (45.7%) during CUD; the difference was statistically significant (P<0.05). Among them, 15 cases (42.9%) with DO were detected both in CUD and AUM, while 12 (34.3%) with DO were not detected in CUD. For the 15 cases with DO detected by both CUD and AUM, the frequency [(3.1±1.0) times/h vs (2.4±0.8) times/h] and maximum value of DO [(22.9±4.5) cmH2O vs (19.2±4.0) cmH2O] in the AUM group were both higher than those in the CUD group (P<0.05). Conclusions: Bladder dysfunction can be diagnosed in children with RMNE using AUM. Furthermore, AUM is more accurate than CUD in evaluating BC, Pmax.det, DO, and other parameters. For children with RMNE and with unsatisfactory CUD results, further AUM examination is recommended to clarify the etiology.

In Situ Formed Ir3Li Nanoparticles as Active Cathode Material in Li-Oxygen Batteries.

Lithium-oxygen (Li-O2) batteries are a promising class of rechargeable Li batteries with a potentially very high achievable energy density. One of the major challenges for Li-O2 batteries is the high charge overpotential, which results in a low energy efficiency. In this work size-selected subnanometer Ir clusters are used to investigate cathode materials that can help control lithium superoxide formation during discharge, which has good electronic conductivity needed for low charge potentials. It is found that Ir particles can lead to lithium superoxide formation as the discharge product with Ir particle sizes of ∼1.5 nm giving the lowest charge potentials. During discharge these 1.5 nm Ir nanoparticles surprisingly evolve to larger ones while incorporating Li to form core-shell structures with Ir3Li shells, which probably act as templates for growth of lithium superoxide during discharge. Various characterization techniques including DEMS, Raman, titration, and HRTEM are used to characterize the LiO2 discharge product and the evolution of the Ir nanoparticles. Density functional calculations are used to provide insight into the mechanism for formation of the core-shell Ir3Li particles. The in situ formed Ir3Li core-shell nanoparticles discovered here provide a new direction for active cathode materials that can reduce charge overpotentials in Li-O2 batteries.

[Epidemiological investigation and analysis of the effect of using diapers on daytime urinary incontinence on children].

Objective: To investigate the relationship between the incidence of daytime urinary incontinence(DUI)and the usage of diapers. Methods: The stratified sampling method was used to investigate the relationship between the incidence of DUI and the usage of diapers on children from 3 to 10 years old from 30 kindergarten and primary schools in Henan Province, China. The survey was carried out in the way of anonymous questionnaire. Results: A total of 8 560 qualified questionnaires(96.2%) were collected and used for statistical analysis. The overall incidence of DUI was 3.52%. With the age increasing, the incidence of DUI was decreased(χ(2)(trend)=75.690, P<0.001) from 6.06% for 3 years old children to 1.82% for 10 years old children. With the time of usage diapers increased, the rate of urination training was significantly reduced(χ(2)(trend)=84.260, P<0.001), and the incidence of DUI was significantly increased(χ(2)(trend)=18.824, P<0.001). With the increase of using diapers, the incidence of DUI increased (χ(2)(trend)=9.234, P<0.01). With the delay of the starting time of urination training, the incidence of DUI was increasing( χ(2)(trend)=9.775, P<0.01). Logistic regression analysis showed that the increase of time of using diapers(OR=1.017, 95% CI: 1.006-1.027, P<0.01)and the increase of frequency of using diapers(OR=1.290, 95% CI: 1.002-1.025, P<0.05)contribute to DUI significantly. Urination training starts from 0 to 6 months was a protective factor against DUI(OR=0.529, 95% CI: 0.345-0.811, P<0.01). Conclusions: The usage of diapers is the risk factor of DUI. It's better to start urination training earlier to help reduce the incidence of DUI in children.

Evaluation of complete and partially obstructed kidneys using Gd-DTPA enhanced dynamic MRI in adolescent swine.

PURPOSE: Aim of this study was to evaluate the dynamic changes in renal relative signal intensity (RSI) following the administration of Gd-DTPA in adolescent pigs with complete and partial unilateral ureteric obstruction. METHODS: Pigs were divided into 3 groups: partial and complete unilateral ureteric obstruction and controls. Complete unilateral ureteric obstruction (CUUO) was created by ligating the left ureter, whereas partial unilateral ureteric obstruction (PUUO) was created in pigs of 2 weeks of age by embedding the left ureter into the psoas muscle. Dynamic MRI was performed before and at 0 - 60 min after an intravenous bolus injection of Gd-DTPA. Mean RSI of the renal cortex, medulla and pelvis was measured and interpreted as an indirect measure of the renal function. In addition, renography was performed, and renal morphology was examined IN VITRO. RESULTS: Three phases of RSI were identified. The dynamic RSI patterns differed markedly between obstructed and control kidneys. In PUUO kidneys, Phase 1 of the mean RSI of the cortex and medulla demonstrated a decreased amplitude and prolonged duration, whereas in Phase 2 the mean RSI of the pelvis was increased. In acute CUUO kidneys, the mean RSI patterns were similar to those of controls, except for a significant increase of the pelvic mean RSI. CONCLUSIONS: Gd-DTPA enhanced dynamic MRI allowed a characterization and differentiation of renal function and morphology of normal and obstructed kidneys, and secondly, provided potentially important information on renal concentrative and filtration availability.

Relationship between brain activity and voiding patterns in healthy preterm neonates.

INTRODUCTION: It remains controversial as to whether the brain affects voiding control in preterm newborns. Constant bladder volume has previously been thought to induce bladder voiding in neonates, with no influence from the brain. Lately, there has been distinct evidence for an existing connection between the central nervous system and bladder voiding in preterm infants, as the voiding reflex arouses neonatal children. Video electroencephalography (EEG) is useful for recording bioelectrical activity of the cerebral cortex and exploring its relationship with voiding patterns in preterm neonates. OBJECTIVE: The objective was to investigate the relationship between voiding patterns and brain activity in healthy preterm neonates by using video-EEG. STUDY DESIGN: Forty-seven healthy preterm neonates (16 females) with a mean postconceptional age (PCA) of 34.1 ± 1.8 weeks were divided according to PCA into three groups: Group I (31-33 weeks, n = 13); Group II (33-35 weeks, n = 14); and Group III (35-37 weeks, n = 20). Video-EEG data from eight cortical regions were recorded from 08:00-12:00, along with 4-hour free voiding patterns and status at voiding (awake/sleep). RESULTS: In Group I, the voiding frequency (VF) was significantly higher and the voiding volume (VV) was significantly lower than in the other groups. There were no significant differences in bladder capacity (BC), bladder capacity/birth weight (BC/BW), postvoiding residual/bladder capacity (PVR/BC), or urinary flow rate (UFR) among the three groups. The Fp1-T3 and Fp2-T4 lead amplitudes significantly differed in Group I and Group II at 5 s before (pre-5), during, and after voiding (post-5). The Fp2-C4 total and theta band lead amplitudes significantly differed across all urination states among the groups. There were no significant differences in electroencephalography frequency among the groups in any urination state. DISCUSSION: There were no significant differences in BC, BC/BW, PVR/BC, or UFR among the three groups, indicating slow bladder function development in preterm neonates. In this study, the EEG amplitude changed in certain pairs of electrodes. These changes might indicate the degree of bladder sensor maturation along with an increasing PCA. This study further suggests that the brain changes in preterm neonates during quiet sleep voiding prominently occur in the right prefrontal cortex and central region. CONCLUSIONS: In preterm neonates, bladder voiding during quiet sleep was accompanied by cortical arousal that might have emanated from a lower center.

What is a representative voiding pattern in children with lower urinary tract symptoms? Lack of consistent findings in ambulatory and conventional urodynamic tests.

BACKGROUND: Conventional urodynamics (CU) is a highly standardized evaluation of lower urinary tract function. However, in pediatric patients there is concern that the reliability of measurements could be influenced by development effects and measurement variability, as well as by the unfamiliar clinical environment. Ambulatory urodynamics (AU) provides an alternative to this - it uses natural filling, is measured over a prolonged period, and is conducted in a child-friendly environment. OBJECTIVE: The aim of this study was to conduct a comparative analysis of AU and CU to evaluate the consistency in voiding patterns obtained with these two methods of urodynamic testing. STUDY DESIGN: Urodynamic parameters obtained by AU and CU methods in 50 pediatric patients aged >5 years were retrospectively analyzed. Voiding patterns were categorized into six types: coordinated contraction, detrusor after-contraction, fluctuated contraction, pre-void contraction, relief voiding, and weak or absent contraction. Voiding patterns were used to determine the repeatability within urodynamic tests and to identify consistency between AU and CU tests. Five urodynamic parameters were quantified and compared between AU and CU: voided volume, flow rate, maximum detrusor pressure, and detrusor pressure at peak flow rate. For inter-observer variation analysis, 100 voiding curves were randomly selected and categorized by two independent observers; inter-observer agreement was evaluated using the kappa statistic. RESULTS: A single pattern of voiding was identified in five patients using AU and 37 using CU. Consistency of a single pattern between AU and CU was identified in three patients, and consistency between a predominant pattern with AU, defined by one type of voiding occurring >50% of one's voids, and a single pattern with CU was identified in 10 patients (summary table). Flow rates were similar between methods; however, higher maximum detrusor pressure and detrusor pressure at peak flow and lower voided volume were recorded with AU. DISCUSSION: AU resulted in more diverse voiding patterns. Along with the differences in measured urodynamic parameters challenges the application of findings from one method to form a clinical diagnosis. Furthermore, CU may not be as sensitive as AU to the variability in lower urinary tract pathophysiology. CONCLUSIONS: More diverse voiding patterns were identified in AU compared with CU, with a lack of consistency in identified voiding pattern in both methods. Therefore, the urodynamic findings in children may have to be analyzed in more detail, taking the variations into account.

Direct observation of electronic-liquid-crystal phase transitions and their microscopic origin in La1/3Ca2/3MnO3.

The ground-state electronic order in doped manganites is frequently associated with a lattice modulation, contributing to their many interesting properties. However, measuring the thermal evolution of the lattice superstructure with reciprocal-space probes alone can lead to ambiguous results with competing interpretations. Here we provide direct observations of the evolution of the superstructure in La1/3Ca2/3MnO3 in real space, as well as reciprocal space, using transmission electron microscopic (TEM) techniques. We show that the transitions are the consequence of a proliferation of dislocations plus electronic phase separation. The resulting states are well described by the symmetries associated with electronic-liquid-crystal (ELC) phases. Moreover, our results resolve the long-standing controversy over the origin of the incommensurate superstructure and suggest a new structural model that is consistent with recent theoretical calculations.

Selection of phage-display peptides that bind specifically to the outer coat protein of Rice black streaked dwarf virus.

Several peptides that could bind specifically to the outer coat protein encoded by the S10 gene of Rice black streaked virus (RBSDV) were isolated from a phage-display random 12-mer peptide library. The sequence analysis showed that the amino acid motif (K)K**(*)P, the asterisk denoting any amino acid, might be the core sequence by which the peptides bind to the target protein. The peptide 1 that had a high affinity to RBSDV outer coat protein was synthesized by a chemical method and its fusion protein with glutathione-S-transferase (GST) was produced in an Escherichia coli expression system. The dot and Western blot analyses indicated that RBSDV could be detected with a high sensitivity in crude extracts of diseased plant leaves using a purified GST fusion protein. The circular dichroism (CD) spectroscopy revealed that the synthesized binding peptide but not a nonbinding peptide could bring about a marked change in the conformation of outer coat RBSDV protein. Since the protein functions only when it has correct conformation, the peptides binding specifically to it could possibly disturb the function of the virus outer coat protein and might be used to block the transmission pathway of the virus. Summing up, as these peptides showed a high specificity and sensitivity and diagnostic potential for RBSDV, they may represent the basis of a novel strategy for development of resistance to RBSDV.

Practical spatial resolution of electron energy loss spectroscopy in aberration corrected scanning transmission electron microscopy.

The resolution of electron energy loss spectroscopy (EELS) is limited by delocalization of inelastic electron scattering rather than probe size in an aberration corrected scanning transmission electron microscope (STEM). In this study, we present an experimental quantification of EELS spatial resolution using chemically modulated 2×(LaMnO(3))/2×(SrTiO(3)) and 2×(SrVO(3))/2×(SrTiO(3)) superlattices by measuring the full width at half maxima (FWHM) of integrated Ti M(2,3), Ti L(2,3), V L(2,3), Mn L(2,3), La N(4,5), La N(2,3) La M(4,5) and Sr L(3) edges over the superlattices. The EELS signals recorded using large collection angles are peaked at atomic columns. The FWHM of the EELS profile, obtained by curve-fitting, reveals a systematic trend with the energy loss for the Ti, V, and Mn edges. However, the experimental FWHM of the Sr and La edges deviates significantly from the observed experimental tendency.

Local structure of layered oxide electrode materials for lithium-ion batteries.

Li-ion batteries are promising candidates for electrical energy storage in applications ranging from portable electronics to hybrid and electric vehicles. In this context, layered compounds in the Li(1+delta)(TM(x)Mn(1-x))(1-delta)O(2) family (TM = transition metal) have received much attention due to their high capacity and stability. In this Research News article we describe recent advances on structural characterization of Li-ion electrode materials using state-of-the-art electron microscopy. Direct evidence of the monoclinic nature of Li(2)MnO(3) has been provided. It has been demonstrated that differences in Z-contrast imaging between Li(2)MnO(3) and LiTMO(2) may be used to screen samples for phase separation in the 10-100 nm scale.

Directed self-assembly of Ge nanostructures on very high index, highly anisotropic Si(hkl) surfaces.

Families of very high-index planes, such as those which bifurcate spontaneously to form a hill-and-valley structure composed of opposing facets, provide natural templates for the directed growth of position-controlled self-organized nanostructures with shapes determined by the facet width ratio R. For example, deposition of a few ML of Ge on Si(173 100 373), corresponding to R(113/517) = 1.7, results in a field of 40-nm-wide Ge nanowires along [72 187] with a uniform period of 60 nm.

Cystometry in infants and children with no apparent voiding symptoms.

OBJECTIVE: To evaluate bladder function in infants and children with no apparent voiding symptoms. SUBJECTS AND METHODS: The study included 83 infants and children (51 boys and 32 girls, aged 3 days to 12 years) with no neurological and lower urinary tract pathology but who had undergone or were about to undergo surgery for upper urinary tract or other pathology. They were evaluated using slow-filling cystometry, with simultaneous electromyography recorded using surface electrodes on the perineum. The voiding variables were compared among groups categorized by age, sex and body weight. RESULTS: In boys and girls, respectively, the mean (SD) post-void residual urine volume (PVR) was 6.3 (3.9) and 5.4 (4.8) mL, the maximum detrusor pressure during voiding was 66.1 (13.1) and 56.6 (14.7) cmH2O and the maximum voiding pressure was 73.9 (16.6) and 62.7 (16.2) cmH2O. There was no significant difference in these variables between the sexes or between infants and children (P > 0.05). Detrusor instability (DI) was apparent in nine of 83 (10.8%) infants and children and occurred in the late filling phase. Bladder capacity increased with age and body weight (from 30 mL in neonates to 350 mL in 12-year-old children), and mean (SD) bladder compliance increased with age, from 3.6 (0.5) mL/cmH2O in infants to 13.3 (3.0) mL/cmH2O in older children, at a filling rate of 5-7 mL/min. CONCLUSIONS: In these infants and children with no apparent voiding symptoms, most bladders were stable, DI could occur in the late filling phase of cystometry, voiding was nearly complete, the PVR being usually < 10 mL, and bladder capacity increased with age and body weight.

Cystometry techniques in female infants and children.

Cystometry is increasingly used in children, being an important diagnostic tool for congenital and acquired malformations such as neurogenic bladder, vesicoureteric reflux, urinary tract infection, urge syndrome, nocturnal enuresis, urinary incontinence and anorectal malformations. During cystometry bladder storage and voiding function can be evaluated. Carefully conducted urodynamic studies provide an insight into the pathophysiologic mechanisms involved in voiding dysfunctions that cannot be obtained by any other diagnostic technique. A variety of methods are available, the most sophisticated being filling and voiding cystometry with flowmetry and electromyography (EMG) under fluoroscopy, i.e. videocystometry. A detailed home recording of the frequency and volume of micturition can provide important clues as to the underlying bladder dysfunction, and can significantly aid in the choice of appropriate investigative techniques, as well as in the interpretation of subsequent urodynamic findings. It must be realized that urodynamic studies are invasive procedures and that artifacts may occur and influence the correct interpretation of the results. Infants and children have a different spectrum of bladder dysfunctions from adults and are generally much less cooperative during a urodynamic study. Therefore, cystometric techniques must be significantly modified. This article reviews cystometry techniques and their application in female infants and children. Cystometry/flow/EMG studies with or without fluoroscopy, ambulatory urodynamics and telemetric urodynamic measurement and their application are outlined.