Strengthening global health security - lessons learned from public health England's international health regulations strengthening project.

BACKGROUND: Country experiences of responding to the challenges of COVID-19 in 2020 highlighted how critical it is to have strong, in-country health security capacity. The UK government has invested in health security capacity development through various projects and agencies, including the UK Department of Health and Social Care, whose Global Health Security Programme provides funding to Public Health England (PHE) to implement health security support. This article describes the results and conclusions of the midterm evaluation, undertaken by Itad, of one of Public Health England's global health projects: International Health Regulations Strengthening, which operates across six countries and works with the Africa Centres for Disease Control. It also highlights some of the key lessons learned for the benefit of other agencies moving into supporting national health security efforts. RESULTS: The Itad team found strong evidence that the IHR Project is well aligned with, and responding to, partners' capability strengthening needs and that the three workstreams - systems coordination, workforce development and technical systems strengthening are implementing relevant and appropriate action to support national priorities. The IHR Project is also aligned with and complementary to other relevant UK development assistance although the Project could strengthen the strategic collaboration with WHO, US CDC and other UK government projects in countries. The Itad team also found that the IHR Project could be more effective if the technical assistance activities were accompanied by relevant materials and equipment while maintaining its supportive role. There was evidence of where technical assistance in the form of training and follow-up mentoring had led to improvements in practice and in IHR compliance, but these were not being systematically captured by the Project's routine reporting. CONCLUSIONS: There was good evidence that the project was doing the right things and aligning its work in the right way, with more limited evidence at the time of the midterm evaluation that it was making progress towards achieving the right results.

Real-time, label-free detection and identification of bacteria through non-invasive optical imaging.

Currently, traditional and newer molecular and mass spectrometry techniques of identifying bacteria from biological samples requires lengthy sample preparation, growth and labelling/staining assays. Thus, there is a pressing clinical need for an adjunct method that accurately identifies bacteria in real time. Here we report on the evaluation of confocal microscopy for the identification of clinically important and multi-drug resistant (MDR) bacteria in real time, using their intrinsic fluorescence features, i.e., emission spectra and fluorescence lifetime. The results demonstrate that difference in emission spectra and fluorescence lifetimes can be used as a fingerprint for identification of 12 bacterial species and MDR strains in real-time. Photostability or time-traces of bacteria demonstrated that these parameters could be used for tracking and recording without a need for labelling. Further, dilution experiments demonstrated that using intrinsic fluorescence S. aureus, Klebsiella pneumoniae and Escherichia coli bacteria can be detected and identified at clinically relevant concentrations as low as 2 × 102 CFU/mL. This non-invasive, non-labelling optical methodology may serve as the basis for development of a device that would quickly and accurately identify bacteria in biological samples. Thus, this intrinsic fluorescence technique would provide clinicians information, within minutes from sampling, to base accurate and specific treatments for patients.

Revealing the Connection Between Hemodialysis and Sexual Physiology in Women With End-Stage Renal Disease.

INTRODUCTION: In the recent past, the procedure of hemodialysis has frequently been opted for patients with end-stage renal disease (ESRD) around the globe. In such patients, the concern of sexual dysfunction is highly prevalent, which causes psychological as well as social deterioration in these patients. Wretchedly, this issue has been ignored in developing countries like Pakistan because of social and cultural constraints.  Objectives: The aim was to measure and compare Female Sexual Functions of Dialysis (FSFI) scores among three comparative groups: healthy controls, pre-dialysis patients, and hemodialysis patients. METHODS: A comparative cross-sectional study was carried out with 60 females aged 22-50 years in which 20 were healthy (controls) and 40 were patients with ESRD; of these 40, 20 were taking only oral medicines (pre-dialysis) and 20 were also receiving hemodialysis (hemodialysis). Married women who could read Urdu and were living with live spouses were included, and those with any psychological or psychiatric illness were excluded. Data was collected through a Likert-scaled questionnaire, Urdu translation of the FSFI questionnaire, and scores of each domain were analyzed. Single-tail one-way ANOVA was used to observe the significant difference among the three comparative groups. RESULTS: A strong statistical difference was observed among the hemodialysis, pre-dialysis, and healthy control groups when these three study groups were compared for the mean scores of all related domains of FSFI questtionarie. In each female sexual domain, i.e. Desire, Arousal, Lubrication, Orgasm, Satisfaction, and Pain, the diseased groups (pre-dialysis and hemodialysis) showed lower sexual scores than the healthy group. The lowest scores were observed in the pre-dialysis group (16.4 ± 6.8) and the highest were noticed in the healthy group (29.9 ± 1.8); the hemodialysis group (23.3 ± 5.0) expressed a moderate pattern of scores in each sexual domain. CONCLUSION: ESRD female patients who were receiving hemodialysis along with routine oral medications showed improved sexual physiology (with better FSFI scores) compared to those who were without hemodialysis.

Detection and identification of amino acids and proteins using their intrinsic fluorescence in the visible light spectrum.

The detection and identification of biomolecules are essential in the modern era of medical diagnostics. Several approaches have been established, but they have significant limitations such as laborious and time-consuming sample preparation, analysis, and the need to use external probes which provide adequate but not desired levels of accuracy and sensitivity. Herein, we have explored successfully a non-invasive technique to detect and identifybiomolecules such as amino acids and proteins by utilizing their intrinsic fluorescence. The developed confocal microscopy method revealed high and photostable emission counts of these biomolecules including amino acids (tryptophan, phenylalanine, tyrosine, proline, histidine, cysteine, aspartic acid, asparagine, isoleucine, lysine, glutamic acid, arginine) and proteins (HSA, BSA) when they are excited with a green laser. The fluorescence lifetime of the samples enabled the identification and distinction of known and blind samples of biomolecules from each other. The developed optical technique is straightforward, non-destructive and does not require laborious labeling to identify specific proteins, and may serve as the basis for the development of a device that would quickly and accurately identify proteins at an amino acid level. Therefore, this approach would open an avenue for precise detection in imaging and at the same time increases our understanding of chemical dynamics at the molecular level.

Protein detection enabled using functionalised silk-binding peptides on a silk-coated optical fibre.

We present a new coating procedure to prepare optical fibre sensors suitable for use with protein analytes. We demonstrate this through the detection of AlexaFluor-532 tagged streptavidin by its binding to D-biotin that is functionalised onto an optical fibre, via incorporation in a silk fibroin fibre coating. The D-biotin was covalently attached to a silk-binding peptide to provide SBP-biotin, which adheres the D-biotin to the silk-coated fibre tip. These optical fibre probes were prepared by two methods. The first involves dip-coating the fibre tip into a mixture of silk fibroin and SBP-biotin, which distributes the SBP-biotin throughout the silk coating (method A). The second method uses two steps, where the fibre is first dip-coated in silk only, then SBP-biotin added in a second dip-coating step. This isolates SBP-biotin to the outer surface of the silk layer (method B). A series of fluorescence measurements revealed that only the surface bound SBP-biotin detects streptavidin with a detection limit of 15 µg mL-1. The fibre coatings are stable to repeated washing and long-term exposure to water. Formation of silk coatings on fibres using commercial aqueous silk fibroin was found to be inhibited by a lithium concentration of 200 ppm, as determined by atomic absorption spectroscopy. This was reduced to less than 20 ppm by dialysis against water, and was found to successfully form a coating on optical fibres.

Silk Fibroin Coated Magnesium Oxide Nanospheres: A Biocompatible and Biodegradable Tool for Noninvasive Bioimaging Applications.

Fluorescent nanoparticles (NPs) have been increasingly studied as contrast agents for better understanding of biological processes at the cellular and molecular level. However, their use as bioimaging tools is strongly dependent on their optical emission as well as their biocompatibility. This work reports the fabrication and characterization of silk fibroin (SF) coated magnesium oxide (MgO) nanospheres, containing oxygen, Cr3+ and V2+ related optical defects, as a nontoxic and biodegradable hybrid platform for bioimaging applications. The MgO-SF spheres demonstrated enhanced emission efficiency compared to noncoated MgO NPs. Furthermore, SF sphere coating was found to overcome agglomeration limitations of the MgO NPs. The hybrid nanospheres were investigated as an in vitro bioimaging tool by recording their cellular uptake, trajectories, and mobility in human skin keratinocytes cells (HaCaT), human glioma cells (U87MG) and breast cancer cells (MCF7). Enhanced cellular uptake and improved intracellular mobilities of MgO-SF spheres compared to MgO NPs was demonstrated in three different cell lines. Validated infrared and bright emission of MgO-SF NP indicate their prospects for in vivo imaging. The results identify the potential of the hybrid MgO-SF nanospheres for bioimaging. This study may also open new avenues to optimize drug delivery through biodegradable silk and provide noninvasive functional imaging feedback on the therapeutic processes through fluorescent MgO.

Multiplexing surface anchored functionalized iron carbide nanoparticle: A low molecular weight proteome responsive nano-tracer.

Harvesting the low molecular weight (LMW) proteins from the cellular exudates is a big challenge for early disease detection. Here, we introduce a unique probe composed of surface-functionalized Fe2C NPs with different functional groups to harvest, identify and profile differentially expressed biomarker proteins. Three different functionalization of Fe2C NPs with Fe2C@NH2, Fe2C@COOH and Fe2C@PEG enabled to harvest 119 differentially expressed proteins from HeLa cell exudates. Among these proteins, 57 were LMW which 82.46 % were up-regulated and 17.54 % were down-regulated. The Fe2C@NH2 were able to separate 60S ribosomal proteins L7a, and L11, and leucine-rich repeat-containing protein 59. These proteins play a vital role in the maturation of large subunit ribosomal ribonucleic acid, mRNA splicing via spliceosome and cancer cell inhibitor, respectively. While, Fe2C@COOH identifies the 60S ribosomal protein types L7, 40S ribosomal protein S11, and 60S ribosomal protein L24. These proteins were important for large ribosomal subunit biogenesis, translational initiation, and assembly of large subunit precursor of pre-ribosome. Finally, the Fe2C@PEG extracted 40S ribosomal protein S2, splicing factor, arginine/serine-rich and 40S ribosomal protein S4, X isoform which were responsible for nonsense-mediated decay, oligodendrocyte differentiation and multicellular organism development. Thus, these results help us in defining oncogenic biomarkers for early disease detection.

Multifunctional Sutures with Temperature Sensing and Infection Control.

The next-generation sutures should provide in situ monitoring of wound condition such as temperature while reducing surgical site infection during wound closure. In this study, functionalized nanodiamond (FND) and reduced graphene oxide (rGO) into biodegradable polycaprolactone (PCL) are incorporated to develop a new multifunctional suture with such capabilities. Incorporation of FND and rGO into PCL enhances its tensile strength by about 43% and toughness by 35%. The sutures show temperature sensing capability in the range of 25-40 °C based on the shift in zero-splitting frequency of the nitrogen-vacancy (NV- ) centers in FND via optically detected magnetic resonance, paving the way for potential detection of infection or excessive inflammation in healing wounds. The suture surface readily coats with antibiotics to reduce bacterial infection risk to the wounds. The new suture thus is promising in monitoring and supporting wound closure.

Environmental impact of co-combustion of polyethylene wastes in a rice husks fueled plant: Evaluation of organic micropollutants and PM emissions.

Co-combustion of biomass and plastic waste has emerged as one of the most promising approach at the plastic waste management challenge. This strategy is particularly attractive since it can simultaneously solve the increasing energy demand and reduce the plastic wastes volume. However, since the combustion of both plastic wastes and natural materials is a potential source of organic micropollutants, such as polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), polychlorinated biphenyls (PCBs) and of polycyclic aromatic hydrocarbons (PAHs), beside particulate matter, the environmental sustainability of the waste to energy (WtE) co-combustion strategy has to be assessed. To this end, the emissions of dioxin like (dl)-PCBs, PCDD/Fs and PAHs from a 4-MW thermal power plant fueled with rice husk, partially replaced by end-of-life polyethylene (PE) industrial waste (up to 15% of the thermal power of the plant), were investigated. GC-MS/MS analyses have demonstrated that the co-combustion of PE waste and rice husk presents a profile of environmental sustainability. The concentrations of dl-PCBs, PCDD/Fs and PAHs were extremely low and they have remained almost unaffected by introducing PE in feed. In particular, emissions of PCCD/Fs and dl-PCBs in flue gas were in the range 0.6-1.0 and 0.2-0.6 pg TEQ/Nm3, respectively, while PAHs concentrations ranged from 410 to 825 ng/Nm3. Furthermore, the emission factors of these organic pollutants were found to be lower with PE increasing rate while particulate matter emissions were not affected by co-combustions. Collectively, the investigation has demonstrated that the noils of the industrial PE, due to the low content in halides and metals, can be used as auxiliary fuel and energetically recycled through co-combustion with rice husk. This case of study represents an effective application of the WtE strategy and a concrete approach to mitigate the threat of plastic pollution.

Real-time detection and identification of nematode eggs genus and species through optical imaging.

Nematode eggs are pervasive pathogens that infect billions of people and livestock every year. Adult parasitic nematode worms can be distinguished based on their size and morphology. However, their eggs, particularly their species Ascaris lumbricoides and Ascaris suum cannot be identified from each other. Identifying eggs of helminths from wastewater and sludge is important from a public health perspective to minimize the spread of Ascaris infections. Numerous methods exist for nematode identification, from a morphological-based approach to high throughput sequencing technology. However, these techniques are not consistent and often laborious and time-consuming. In this study, we demonstrate that non-invasive real-time identification of eggs is possible based on their intrinsic fluorescence. Using confocal microscopy, we investigate the autofluorescence properties of five species of nematode eggs and observe clear differences between genus and for the first time their species in sludge samples. This non-invasive imaging technique could lead to better understanding of these species and may assist in early control of diseases.

Electrospun Nanodiamond-Silk Fibroin Membranes: A Multifunctional Platform for Biosensing and Wound-Healing Applications.

Next generation wound care technology capable of diagnosing wound parameters, promoting healthy cell growth, and reducing pathogenic infections noninvasively would provide patients with an improved standard of care and accelerated wound repair. Temperature is one of the indicating biomarkers specific to chronic wounds. This work reports a hybrid, multifunctional optical material platform-nanodiamond (ND)-silk membranes as biopolymer dressings capable of temperature sensing and promoting wound healing. The hybrid structure was fabricated through electrospinning, and 3D submicron fibrous membranes with high porosity were formed. Silk fibers are capable of compensating for the lack of an extracellular matrix at the wound site, supporting the wound-healing process. Negatively charged nitrogen vacancy (NV-) color centers in NDs exhibit optically detected magnetic resonance (ODMR) and act as nanoscale thermometers. This can be exploited to sense temperature variations associated with the presence of infection or inflammation in a wound, without physically removing the dressing. Our results show that the presence of NDs in the hybrid ND-silk membranes improves the thermal stability of silk fibers. NV- color centers in NDs embedded in silk fibers exhibit well-retained fluorescence and ODMR. Using the NV- centers as fluorescent nanoscale thermometers, we achieved temperature sensing in 25-50 °C, including the biologically relevant temperature window, for cell-grown ND-silk membranes. An enhancement (∼1.5× on average) in the temperature sensitivity of the NV- centers was observed for the hybrid materials. The hybrid membranes were further tested in vivo in a murine wound-healing model and demonstrated biocompatibility and equivalent wound closure rates as the control wounds. Additionally, the hybrid ND-silk membranes exhibited selective antifouling and biocidal propensity toward Gram-negative Pseudomonas aeruginosa and Escherichia coli, while no effect was observed on Gram-positive Staphylococcus aureus.

Biocompatible and Biodegradable Magnesium Oxide Nanoparticles with In Vitro Photostable Near-Infrared Emission: Short-Term Fluorescent Markers.

Imaging of biological matter by using fluorescent nanoparticles (NPs) is becoming a widespread method for in vitro imaging. However, currently there is no fluorescent NP that satisfies all necessary criteria for short-term in vivo imaging: biocompatibility, biodegradability, photostability, suitable wavelengths of absorbance and fluorescence that differ from tissue auto-fluorescence, and near infrared (NIR) emission. In this paper, we report on the photoluminescent properties of magnesium oxide (MgO) NPs that meet all these criteria. The optical defects, attributed to vanadium and chromium ion substitutional defects, emitting in the NIR, are observed at room temperature in NPs of commercial and in-house ball-milled MgO nanoparticles, respectively. As such, the NPs have been successfully integrated into cultured cells and photostable bright in vitro emission from NPs was recorded and analyzed. We expect that numerous biotechnological and medical applications will emerge as this nanomaterial satisfies all criteria for short-term in vivo imaging.

Recovery profile - a comparison of isoflurane and propofol anesthesia for laparoscopic cholecystectomy.

OBJECTIVE: To compare the recovery profile in terms of time of extubation, eye opening, orientation and mobility and frequency of Postoperative Nausea and Vomiting (PONV) between propofol and isoflurane based anesthesia in patients undergoing laparoscopic cholecystectomy with prophylactic antiemetic. STUDY DESIGN: Quasi-experimental study. PLACE AND DURATION OF STUDY: Department of Anesthesia, Civil Hospital and Dow University of Health Sciences, Karachi, from January to April 2007. PATIENTS AND METHODS: After informed consent, a total of 60 ASA I-II patients scheduled for laparoscopic cholecystectomy were divided in two equal groups I and P. Anesthesia in all patients were induced by Nalbuphine 0.15 mg/kg, Midazolam 0.03 mg/kg, Propofol 1.5 mg/kg and Rocuronium 0.6 mg/kg. Anesthesia was maintained with Isoflurane in group I and propofol infusion in group P, while ventilation was maintained with 50% N2O/O2 mixture in both the groups. All patients were given antiemetic prophylaxis. Hemodynamics were recorded throughout anesthesia and recovery period. At the end of surgery, times of extubation, eye opening, orientation (by modified Aldrete score) and mobility (recovery profile) were assessed. PONV was observed and recorded immediately after extubation, during early postoperative period (0-4 hours) and late period (4-24 hours). Antiemetic requirements were also recorded for the same periods in both the groups. RESULTS: Propofol provided faster recovery (extubation and eye opening times) and orientation in immediate postoperative period with statistically significant differences between the groups (p<0.0001). Recovery characteristics were comparably lower in group I. More patients achieved full points (8) on modified Aldrete score at different time until 30 minutes in group P. Postoperative nausea and vomiting in early and late periods were significantly reduced in group P. Moreover, requirement of rescue antiemetic doses were significantly lower in group P in 24 hours (p<0.0001). CONCLUSION: In this series, recovery was much faster with earlier gain of orientation with propofol anesthesia compared to isoflurane in the early recovery periods. Propofol is likely to be a better choice of anesthesia because of its better antiemetic property that persists long into postoperative period and reduces the risk of PONV.

Single dose caudal tramadol with bupivacaine and bupivacaine alone in pediartic inguinoscrotal surgeries.

OBJECTIVE: To determine the postoperative analgesic effect of Tramadol when given with caudally administered Bupivacaine in children undergoing inguinoscrotal surgeries. STUDY DESIGN: Quasi-experimental study. PLACE AND DURATION OF STUDY: Department of Anaesthesia, Dow University of Health Sciences and Civil Hospital Karachi, from July 2005 to March 2006. PATIENTS AND METHODS: A total of 60 children, undergoing inguinoscrotal surgeries, aged from 1 to 12 years, ASA 1 and 2, were included. The patients were divided into two equal groups. The group given Bupivacaine with Tramadol was called 'group BT' and the group which was given only Bupivacaine was labeled as 'group B'. Group BT was given 0.25%,0.8 ml/kg Bupivacaine and Tramadol 2 mg/kg while the other group B was given 0.25%, 0.8 ml/kg Bupivacaine through caudal route after induction of general anesthesia. No other analgesic was given intraoperatively. The postoperative pain was evaluated by using visual analogue scale/Ocher's face scale/CHEOPS and sedation was assessed by 5 points sedation score at immediate postoperative period 1, 2,3,4,6, 12 and 24 hours. Supplemental analgesia in the form of paracetamol suppositories and syrup Ibuprofen was given accordingly. SaO2, pulse, blood pressure, and motor block were monitored in all the patients. RESULTS: Addition of Tramadol with Bupivacaine resulted in meaningfully increased postoperative analgesic period (16.06 +/- 4.04 hours). No other side effects like respiratory depression, pruritus, urinary retention were found in both the groups except for nausea and vomiting. The demand for supplemental analgesia was more in the patients belonging to B group than BT group. The sedation scores were similar in both the groups. CONCLUSION: The use of Tramadol as an additive with local anesthetics can prolong the postoperative analgesic period when administered caudally. Its use is safe in children.

Doxorubicin loaded nanodiamond-silk spheres for fluorescence tracking and controlled drug release.

Nanoparticle (NP) based technologies have proved to be considerably beneficial for advances in biomedicine especially in the areas of disease detection, drug delivery and bioimaging. Over the last few decades, NPs have garnered interest for their exemplary impacts on the detection, treatment, and prevention of cancer. The full potential of these technologies are yet to be employed for clinical use. The ongoing research and development in this field demands single multifunctional composite materials that can be employed simultaneously for drug delivery and biomedical imaging. In this manuscript, a unique combination of silk fibroin (SF) and nanodiamonds (NDs) in the form of nanospheres are fabricated and investigated. The spheres were loaded with the anthracyline Doxorubicin (DoX) and the drug release kinetics for these ND-SF-DoX (NDSX) spheres were studied. NDs provided the fluorescence modality for imaging while the degradable SF spheres stabilized and released the drug in a controlled manner. The emission and structural properties of the spheres were characterized during drug release. The degradability of SF and the subsequent release of DoX from the spheres were monitored through fluorescence of NDs inside the spheres. This research demonstrates the enormous potential of the ND-SF nanocomposite platforms for diagnostic and therapeutic purposes, which are both important for pharmaceutical research and clinical settings.

Heat Transfer in MHD Mixed Convection Flow of a Ferrofluid along a Vertical Channel.

This study investigated heat transfer in magnetohydrodynamic (MHD) mixed convection flow of ferrofluid along a vertical channel. The channel with non-uniform wall temperatures was taken in a vertical direction with transverse magnetic field. Water with nanoparticles of magnetite (Fe3O4) was selected as a conventional base fluid. In addition, non-magnetic (Al2O3) aluminium oxide nanoparticles were also used. Comparison between magnetic and magnetite nanoparticles were also conducted. Fluid motion was originated due to buoyancy force together with applied pressure gradient. The problem was modelled in terms of partial differential equations with physical boundary conditions. Analytical solutions were obtained for velocity and temperature. Graphical results were plotted and discussed. It was found that temperature and velocity of ferrofluids depend strongly on viscosity and thermal conductivity together with magnetic field. The results of the present study when compared concurred with published work.

Unsteady MHD Thin Film Flow of an Oldroyd-B Fluid over an Oscillating Inclined Belt.

This paper studies the unsteady magnetohydrodynamics (MHD) thin film flow of an incompressible Oldroyd-B fluid over an oscillating inclined belt making a certain angle with the horizontal. The problem is modeled in terms of non-linear partial differential equations with some physical initial and boundary conditions. This problem is solved for the exact analytic solutions using two efficient techniques namely the Optimal Homotopy Asymptotic Method (OHAM) and Homotopy Perturbation Method (HPM). Both of these solutions are presented graphically and compared. This comparison is also shown in tabular form. An excellent agreement is observed. The effects of various physical parameters on velocity have also been studied graphically.

Lifetime Reduction and Enhanced Emission of Single Photon Color Centers in Nanodiamond via Surrounding Refractive Index Modification.

The negatively-charged nitrogen vacancy (NV(-)) center in diamond is of great interest for quantum information processing and quantum key distribution applications due to its highly desirable long coherence times at room temperature. One of the challenges for their use in these applications involves the requirement to further optimize the lifetime and emission properties of the centers. Our results demonstrate the reduction of the lifetime of NV(-) centers, and hence an increase in the emission rate, achieved by modifying the refractive index of the environment surrounding the nanodiamond (ND). By coating the NDs in a polymer film, experimental results and numerical calculations show an average of 63% reduction in the lifetime and an average enhancement in the emission rate by a factor of 1.6. This strategy is also applicable for emitters other than diamond color centers where the particle refractive index is greater than the refractive index of the surrounding media.

Fluorescent Nanodiamond Silk Fibroin Spheres: Advanced Nanoscale Bioimaging Tool.

High resolution bioimaging is not only critical to the study of cellular structures and processes but it also has important applications in drug delivery and therapeutics. Fluorescent nanodiamonds (NDs) are excellent candidates for long-term bioimaging and tracking of biological structures at the nanoscale. Encapsulating NDs in natural biopolymers like silk fibroin (SF) widens their biomedical applications. Here we report the synthesis, structural and optical characterization of ND incorporated SF nanospheres. The photoluminescence from optical defects within the NDs is found to increase when encapsulated in the SF spheres. The encapsulated NDs are applied in vitro to investigate the intracellular mobility compared to bare NDs. The diffusion rate of encapsulated NDs is shown to improve due to SF coating. These ND-SF spheres are envisioned as highly suitable candidates for bioinjectable imaging and drug release carriers for targeted drug delivery applications.

Irregular or absent periods--what can an ultrasound scan tell you?

Transvaginal ultrasonography has increased our appreciation of the physiological changes in the ovary and endometrium that occur during the normal menstrual cycle. It has become a primary investigative tool in women with irregular or absent periods. Its usefulness in cases of primary amenorrhoea to assess anatomy is also undisputed although it may have limitations in terms of its specificity. However, the interpretation of ultrasound images in women with irregular menses or secondary amenorrhoea is not entirely straightforward. This is particularly true in the diagnosis of polycystic ovary syndrome, a condition of uncertain aetiology, which may present with oligoamenorrhoea. This chapter aims to discuss the benefits and limitations of ultrasound while taking into account the broad overlap between normal and abnormal physiology, some of which has still to be elucidated.