Modelling and optimization of factors influencing adsorptive performance of agrowaste-derived Nanocellulose Iron Oxide Nanobiocomposites during remediation of Arsenic contaminated groundwater

Nanocellulose Iron Oxide Nanobiocomposites (NIONs) were synthesized from rice husk and sugarcane bagasse derived nanocelluloses for adsorptive removal of arsenic and associated contaminants present in groundwater samples. These NIONSs were superparamagnetic, hence magnetically recoverable and demonstrated promising recyclability. Synthesis of NIONs was confirmed by Transmission electron microscopy (TEM), X-Ray Diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopic (XPS). FTIR and XPS data together with adsorption kinetics provide insights into probable adsorption mechanism of Arsenic by NIONs. The experimental conditions for 10 different variants were modelled using response surface methodology (RSM) based on central composite design (CCD), considering the parameters; adsorbate dosage, adsorbent dosage, pH and contact time. The results identified the best performing variants and the optimal conditions for maximal absorption (~99%). These results were validated using a three-layer feed-forward Multilayer Perceptron (MLP) based Artificial Neural Network (ANN) model. Both RSM and ANN chemometric models were in close conformity for optimized conditions of highest adsorption by specific variants. The standardized conditions were used to expand the study to field-based arsenic contaminated groundwater samples and their performance to commercial adsorbents. NIONs show promising commercial potential for water remediation applications due to their high adsorptive performance, magnetic recoverability and recyclability.

Iron oxide Permeated Mesoporous rice-husk nanobiochar (IPMN) mediated removal of dissolved arsenic (As): Chemometric modelling and adsorption dynamics

Adsorption based technologies are most widely used to mitigate the global predominance of heavy-metal groundwater contaminants like Arsenic (As), owing to their high efficiency and economic operation. The current study involves the optimization of Iron oxide Permeated Mesoporous rice-husk nanobiochars (IPMN) for As removal, which were synthesized through a chemically amended pyrolytic approach. The IPMN variants were screened based on preliminary OVAT (one-variable-at-a-time) studies for As removal. Chemometric investigations employing a central composite design matrix of Response surface methodology was further used to understand the influence of the process parameters on the adsorption of As on the most efficient IPMN variant. A Multi-Layered-Perceptron based artificial neural network was further used to confirm the veracity of the experimental and predictive conditions, to derive the optimal condition for the best adsorption efficiency. In addition, the dynamics of As adsorption by the optimal IPMN variant was modelled using pseudo-first-order (Lagergren) and pseudo-second-order (Ho) rate kinetic equations followed by isotherm studies using non-linear regression of Langmuir, Freundlich and Sips adsorption isotherms. The IPMNs have an appreciably higher uptake capacity (>90%) for dissolved As, as compared to the native milled rice husk (∼20%), alongside a substantial recyclability, thereby establishing their potential as a highly efficient, economical and sustainable nanobiochar for As removal.

Normal ranges for anorectal manometry and sensation in women of reproductive age

OBJECTIVE

To derive a range of normal values for anal sphincter resting and squeeze pressure, and anorectal sensation in healthy women without anorectal disease before and after their first childbirth.

METHOD

Nulliparous women undergoing anal physiology testing in the third trimester of pregnancy and 12 weeks after delivery. All were asked to undergo anal manometry and anorectal electrosensation testing. Maximum resting pressure, maximum squeeze pressure and anal thresholds to electrical current were assessed at 1 cm intervals down the anal canal. Rectal electrosensitivity thresholds were assessed 10 cm from the anal verge.

RESULTS

A total of 286 women attended for antenatal investigations and 161 (56%) returned postpartum. The anal canal length was 3.9 +/- 0.6 cm antenatally and 3.9 +/- 0.6 cm postnatally. During pregnancy the 95% normal range for anal resting and squeeze pressures, anal and rectal sensation were 29-90 mmHg, 50-163 mmHg, 2-31 mA and 3-33 mA respectively. Post delivery the 95% normal ranges were 27-98 mmHg, 43-156, 2-12 mA and 0.1-34 mA respectively. Both antenatally and postnatally the manometry and sensitivity values were similar in women with and without bowel symptoms.

CONCLUSION

This study is the largest series of normative data for anal manometry, and anorectal sensation in women before and after their first delivery. The antenatal values can serve to represent ranges for nulliparous women and the postnatal values ranges in primiparous women.

Direct imaging of the pelvic floor muscles using two-dimensional ultrasound: a comparison of women with urogenital prolapse versus controls

OBJECTIVE

To evaluate the anatomy of the levator ani muscle in women with urogenital prolapse versus matched controls without prolapse using real-time two-dimensional (2-D) ultrasound.

DESIGN

Prospective observational study.

SETTING

Tertiary referral urogynaecology unit.

POPULATION

Forty-three women with pelvic organ prolapse (POP) and 24 women (controls) attending a gynaecology clinic without prolapse.

METHODS

All participants completed a standardised symptom questionnaire.

MAIN OUTCOME MEASURES

The morphology of the vagina and paravaginal tissue was recorded at different levels. The thickness of the levator ani and the hiatal area were measured at rest. Reproducibility of the method was assessed by repeated measurements to assess intra-observer variability and inter-observer variability.

RESULTS

This method showed good intra-observer and inter-observer reproducibility and reliability. In controls, the pubococcygeus muscle showed more regular echogenicity with no evidence of trauma, whereas in women with prolapse the muscle had mixed echogenicity. (P = 0.002). The mean thickness of the pubococcygeus did not differ between groups. The levator hiatal area was significantly larger in women with pelvic floor prolapse versus controls (17.8 cm2 versus 13.5 cm2, P < 0.001). This increase in hiatal area positively and significantly correlated with prolapse severity (P < 0.001).

CONCLUSIONS

Morphology and hiatal area can be reliably imaged using 2-D ultrasound. Prolapse was related to changes in pelvic floor morphology and increased levator hiatal area. The use of 2-D ultrasound provides an important insight into the pathophysiology of prolapse.

Urological problems in pregnancy

During pregnancy the urinary tract undergoes extensive anatomical and physiological changes. These changes can result in many symptoms and pathological conditions that may affect the mother and fetus. It is well documented that childbirth may result in urinary tract damage which may predispose to postpartum symptoms. This review describes the physiological and pathological consequences of pregnancy and delivery on the urinary tract, and how these may be minimized.

Anal function: effect of pregnancy and delivery

OBJECTIVE

To investigate the effect of pregnancy and delivery on anal continence, sensation, manometry, and sphincter integrity.

STUDY DESIGN

Two hundred eighty-six nulliparous women in the third trimester completed a symptom questionnaire and underwent anorectal sensation and manometric evaluations. Three months postpartum, 161 women returned and the questionnaires and investigations were repeated together with anal endosonographic examinations.

RESULTS

The prevalence of fecal urgency before, during, and after pregnancy was 1%, 9.4%, and 10.5%, respectively; the prevalence of anal incontinence before, during, and after pregnancy was 1.4%, 7.0%, and 8.7%, respectively. Vaginal delivery, particularly instrumental, resulted in a decrease in anal squeeze pressures (P =.015) and resting pressures (P =.002) but had no effect on anal sensation. Postpartum anal endosonographic examination revealed sphincter disruption in 38% of women. There was no relationship between symptoms and anal manometry, sensation, or sphincter integrity. Vaginal delivery (P <.0001) and perineal trauma (P <.001) were significantly associated with sphincter defects.

CONCLUSION

Vaginal delivery is associated with a decrease in anal pressures and increased anal sphincter trauma but has no effect on anal sensation. These changes were not related to anal symptoms.

Pregnancy and delivery: a urodynamic viewpoint

OBJECTIVE

The aims of this study were to establish prospectively the prevalence of objective bladder dysfunction before and after delivery by means of urodynamic investigations and to assess the effect of obstetric variables on bladder function.

DESIGN

Prospective longitudinal study. Twin channel subtracted cystometry was performed in the standing and sitting position, with a cough stress test at the end of filling. The investigations were repeated three months postpartum.

PARTICIPANTS

Two hundred and eighty-six nulliparae with singleton pregnancies who were delivered between April 1996 and November 1997 attended for antenatal assessment after 34 weeks of gestation and 161 who returned postpartum.

SETTING

Department of Obstetrics and Gynaecology in a London teaching hospital.

RESULTS

The mean urodynamic values both in pregnancy and postpartum lower than values defined in a non-pregnant population. The prevalence of genuine stress incontinence and detrusor instability were antenatally 9% and 8%, respectively, and postpartum 5% and 7%, respectively. Obstetric and neonatal factors were not related to urodynamic variables.

CONCLUSIONS

Despite the reported high prevalence of urinary incontinence related to pregnancy and childbirth, neither pregnancy nor delivery resulted in any consistent effects on objective bladder function. Postpartum urodynamic measurements were not related to either obstetric or neonatal variables, but were dependent on antenatal values.

Antenatal prediction of postpartum urinary and fecal incontinence

OBJECTIVE

To investigate the effect of pregnancy and delivery on continence and to assess whether physical markers of collagen weakness can predict postpartum urinary and fecal incontinence (including incontinence of flatus).

METHODS

In a prospective, longitudinal study in a London teaching hospital, 549 nulliparas were interviewed after 34 weeks' gestation and again 3 months postpartum regarding urinary and fecal symptoms before and during pregnancy and after delivery. Family histories of incontinence, prolapse, and collagen abnormalities were recorded also. Physical examination was done to assess markers of collagen weakness such as striae, hernia, varicose veins, and joint mobility.

RESULTS

The prevalence of urinary incontinence before, during, and after pregnancy was 3.6%, 43.7%, and 14.6%, and rates of fecal incontinence were 0.7%, 6.0%, and 5.5%, respectively. Fecal urgency was more common in women who had spontaneous and instrument-assisted vaginal deliveries (n = 413) compared with cesareans (n = 131) (7.3% versus 3.1%; P = .046). Postnatal urinary or fecal dysfunction was not related to antenatal body mass index, smoking, race, striae, varicose veins, hemorrhoids, or family history of incontinence. Higher joint-mobility scores were associated with incontinence of flatus (P = .021) but not with other urinary or fecal symptoms.

CONCLUSION

Although collagen weakness was previously implicated in the pathogenesis of incontinence, physical markers in this study could not predict postpartum urinary and fecal incontinence. Either those markers were not representative of collagen weakness, or a larger study with longer follow-up is necessary.

The ethnic cultural and social aspects of incontinence--a pilot study

This cross-sectional study aimed to study the religious and cultural practices of ethnic minorities that might affect the experience and ideas that sufferers of incontinence have. Subjects were multiparous women from the local community who suffered from incontinence. Structured and unstructured interviews were conducted to assess the effect of incontinence and menstruation on home life, sexual life, personal and communal prayer, rules and customs associated with menstruation, and the ability to discuss problems with their doctor and partners. Individual women differed in how they rated their daily activities, and this was not related to religious or ethnicity. Higher restrictions on activity were perceived for fecal than for urinary incontinence. Sexual relationships were restricted for Jewish and Muslim women during menses. Incontinence led to religious restriction, which was most marked for Jewish and Muslim women, and this was related to the need for cleanliness for prayer. Less then 50% of patients sought help, and this was not related to duration and severity of symptoms. Only Muslim women had a strong preference for female doctors, and this was for cultural reasons.

Trisomy 2 in an acardiac twin in a triplet in-vitro fertilization pregnancy

A case is reported of twin reversed arterial perfusion (TRAP) sequence in a triamniotic dichorionic triplet pregnancy conceived by in-vitro fertilization which was diagnosed at 25 weeks of gestation by colour Doppler sonography. It highlights the risk of monochorionicity-associated morbidity in multiple pregnancies obtained by assisted conception and stresses the importance of chorionicity determination by early ultrasound examination. Cytogenetic analysis of skin from the acardius showed trisomy 2 in all cells, whereas the karyotype in the monochorionic triplet was normal. This is an example of heterokaryotypic monozygotism where the chromosomal abnormality must have occurred during the early cleavage divisions. Aneuploidy as a possible aetiological factor of TRAP sequence is discussed.

Nine year survey of 138 ectopic pregnancies

During the nine years (1986-1994), 138 women underwent surgery for ectopic pregnancies (One for every 213 deliveries). The commonest presenting symptom was abdominal pain (96%) followed by vaginal bleeding (83%). Four patients were asymptomatic and were diagnosed at a routine antenatal ultrasound scan. The most frequent physical findings were abdominal tenderness (87%) and followed by adnexal tenderness (57%). Histories of infertility in 17%, use of intrauterine contraceptive device (13%), and previous ectopic pregnancy in 11% were elicited. Eleven patients (8%) had a false negative urinary pregnancy test and subsequently required surgery. The ectopic pregnancies were tubal in 97% of the cases. There were 3 ovarian ectopics and one cervical ectopic.

Female urethral diverticula

Most urethral diverticula should be diagnosed on clinical grounds alone, but investigations may be used to confirm the diagnosis in difficult cases, delineate the extent of the disease and investigate other entities such as stress incontinence. A high index of suspicion is required when assessing women with lower urinary tract symptoms to ensure that cases of urethral diverticulum are not missed. The cases presented demonstrate that greater awareness of the signs and symptoms of this not uncommon disease may facilitate early diagnosis. Our cases also show that surgical treatment is effective and worthwhile.