Polyhydroxyalkanoates (PHAs) are biodegradable polyesters produced by microorganisms, under unbalanced growth conditions, as a carbon storage compound. PHAs are composed of various monomers such as 3-hydroxybutyrate (3HB) and 3-hydroxyhexanoate (3HHx). Silk fibroin (SF) derived from Bombyx mori cocoons, is a widely studied protein polymer commonly used for biomaterial applications. In this study, non-woven electrospun films comprising a copolymer of 3HB and 3HHx [P(3HB-co-3HHx)], SF and their blends were prepared by electrospinning technique. The growth and osteogenic differentiation of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) were studied using different types of fabricated electrospun films. The differentiation study revealed that electrospun P(3HB-co-3HHx)/SF film supports the differentiation of hUC-MSCs into the osteogenic lineage, confirmed by histological analysis using Alizarin Red staining, energy dispersive X-ray (EDX) and quantitative real-time PCR analysis (qPCR). Electrospun P(3HB-co-3HHx)/SF film up-regulated the expression of osteogenic marker genes, alkaline phosphatase (ALP) and osteocalcin (OCN), by 1.6-fold and 2.8-fold respectively, after 21 days of osteogenic induction. In conclusion, proliferation and osteogenic differentiation of hUC-MSCs were enhanced through the blending of P(3HB-co-3HHx) and SF. The results from this study suggest that electrospun P(3HB-co-3HHx)/SF film is a promising biomaterial for bone tissue engineering.
In this study, a series of copper-ion-doped titanium dioxide (Cu-ion-doped TiO₂) nanotubes (NTs) were synthesized via a hydrothermal method by the concentration variation of doped Cu ions (0.00, 0.50, 1.00, 2.50, and 5.00 mmol). In addition, the samples were characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX), nitrogen gas adsorption measurements, and ultraviolet-visible (UV-Vis) diffuse-reflectance spectroscopy. The photocatalytic activity of the Cu-iondoped TiO₂ NTs was investigated for the degradation of methyl orange (MO) under sunlight. The results obtained from the structural and morphological studies revealed that, at low concentrations of Cu-doped TiO₂ NTs, Cu is incorporated into the interstitial positions of the TiO₂ lattice, affording a new phase of TiO₂ (hexagonal) instead of the anatase TiO₂ (tetragonal) observed for undoped TiO₂ NTs. EDX analysis confirmed the presence of Cu in the TiO₂-based photocatalyst. All of the investigated samples exhibited a hollow fibrous-like structure, indicative of an NT morphology. The inner and outer diameters of the NTs were 4 nm and 10 nm, respectively. The photocatalysts exhibited a large surface area due to the NT morphology and a type IV isotherm and H3 hysteresis, corresponding to the mesopores and slit-shaped pores. The Cu-ion-doped TiO₂ NTs were excited by sunlight because of their low bandgap energy; and after the incorporation of Cu ions into the interstitial positions of the TiO₂ lattice, the NTs exhibited high visible-light activity owing to the low bandgap.
Titanate compounds was synthesized using hydrothermal method at various temperature (100, 150, 200, and 250 °C) for 24 hours. As-synthesized titanate was characterized using FTIR, XRD and nitrogen gas adsorption. FTIR spectra was scanned from 4000 to 400 cm-1 using Perkin Elmer Spectrum 100 FTIR spectrophotometer. XRD diffractogram was performed by using Rigaku Miniflex (II) X-ray diffractometer operating at a scanning rate of 2.00° min-1. The diffraction spectra were recorded at the diffraction angle, 2θ from 10° to 80° at room temperature. Nitrogen gas adsorption analysis was studied by using Micromeritics ASAP2020 (Alaska) to determine the surface area and pores size distribution. The nitrogen adsorption and desorption was measured at 77 K (temperature of liquid nitrogen) and the samples were degassed in a vacuum at 110 °C under nitrogen flow for overnight prior to analysis.
The application of graphene in the field of drug delivery has attracted massive interest among researchers. However, the high toxicity of graphene has been a drawback for its use in drug delivery. Therefore, to enhance the biocompatibility of graphene, a new route was developed using ternary natural deep eutectic solvents (DESs) as functionalizing agents, which have the capability to incorporate various functional groups and surface modifications. Physicochemical characterization analyses, including field emission scanning electron microscope, fourier-transform infrared spectroscopy, Raman spectroscopy, Brunauer-Emmett-Teller, X-ray diffraction, and energy dispersive X-ray, were used to verify the surface modifications introduced by the functionalization process. Doxorubicin was loaded onto the DES-functionalized graphene. The results exhibited significantly improved drug entrapment efficiency (EE) and drug loading capacity (DLC) compared with pristine graphene and oxidized graphene. Compared with unfunctionalized graphene, functionalization with DES choline chloride (ChCl):sucrose:water (4:1:4) resulted in the highest drug loading capacity (EE of 51.84% and DLC of 25.92%) followed by DES ChCl:glycerol:water (1:2:1) (EE of 51.04% and DLC of 25.52%). Following doxorubicin loading, graphene damaged human breast cancer cell line (MCF-7) through the generation of intracellular reactive oxygen species (>95%) and cell cycle disruption by increase in the cell population at S phase and G2/M phase. Thus, DESs represent promising green functionalizing agents for nanodrug carriers. To the best of our knowledge, this is the first time that DES-functionalized graphene has been used as a nanocarrier for doxorubicin, illustrating the potential application of DESs as functionalizing agents in drug delivery systems.
The synthesis of graphene by double thermal chemical vapor deposition (DTCVD) using waste of industrial cooking oil (WICO) as a natural carbon source was investigated. The synthesis parameter (Argon gas flow rate) was varied between 50sccm to 300sccm by 50sccm increments. The function of Argon gas is to provide ambient condition, remove the atmospheric air from the tube and could improve the crystallinity of graphene during synthesis. WICO (from AYAMAS food processing) was placed in the first furnace (precursor furnace) and nickel was placed in the second furnace (deposition furnace). During the synthesis, elevated quantities of carbon from the source material are separated and precipitated on the Nickel surface. The sample were characterized by using Field Emission Scanning Electron Microscopy (FESEM), X-Ray Diffraction (XRD), Energy Dispersive X-ray (EDX), and Ultraviolet Visible (UV-Vis) spectroscopy. Based on FESEM images, at 250sccm, hexagonal graphene formation was observed. Besides, optical properties can be seen by UV-Vis and as the results show that 250sccm is the highest reflectivity value. Consequently, graphene synthesis from WICO using various Argon gas flow rate as precursor is successfully demonstrated.
Two organometallic compounds known as (E)-1-ferrocenyl-(3-fluorophenyl)prop-2-en-1-one (Fc1) and (E)-1-ferrocenyl-(3-fluoro-4-methoxyphenyl)prop-2-en-1-one (Fc2) are designed and synthesized for application in dye-sensitized solar cell (DSSC) based on a donor-π-acceptor (D-π-A) architecture. By strategically introducing a methoxy group into the acceptor side of the compound, Fc2 which has adopted a D-π-A-AD structure are compared with the basic D-π-A structure of Fc1. Both compounds were characterized by utilizing the IR, NMR and UV-Vis methods. Target compounds were further investigated by X-ray analysis and studied computationally using Density Functional Theory (DFT) and Time-Dependent DFT (TD-DFT) approaches to explore their potential performances in DSSCs. An additional methoxy group has been proven in enhancing intramolecular charge transfer (ICT) by improving the planarity of Fc2 backbone. This good electronic communication leads to higher HOMO energy level, larger dipole moment and better short-circuit current density (Jsc) values. Eventually, the presence of methoxy group in Fc2 has improved the conversion efficiency as in comparison to Fc1 under the same conditions.
For x- and gamma- irradiations delivering entrance doses from 2- up to 1000 Gy to commercial 1.0 mm thick borosilicate glass microscope slides, study has been made of their thermoluminescence yield. With an effective atomic number of 10.6 (approximating bone equivalence), photon energy dependency is apparent in the low x-ray energy range, with interplay between the photoelectric effect and attenuation. As an example, over the examined dose range, at 120 kVp the photon sensitivity has been found to be some 5× that of 60Co gamma irradiations, also with repeatability to within ~1%. The glow-curves, taking the form of a single prominent broad peak, have been deconvolved yielding at best fit a total of five peaks, the associated activation energies and frequency factors also being obtained. The results indicate borosilicate glass slides to offer promising performance as a low-cost passive radiation dosimeter, with utility for both radiotherapy and industrial applications.
Phasic ECG voltage changes or electrical alternans is a well-described ECG changes seen in the pericardial effusion and cardiac tamponade. Popular as once believed, this ECG features are no longer considered pathognomonic for pericardial effusion and cardiac tamponade. Electric alternans is observed in pneumothorax especially left-sided pneumothorax. This is a case of a 41-year-old man who presented with chest pain and breathlessness to the emergency department. Assessment in the emergency unit revealed an obvious distress man with a respiratory rate of 60 breaths/min with cyanosis There were generalised rhonchi and prolonged expiratory breath sound appreciated. Chest X-ray (CXR) was done and diagnosed to have left tension pneumothorax. Initial electrocardiogram (ECG) showed electrical alternans in all leads. He was intubated for respiratory distress followed by chest tube insertion. His initial ECG findings resolved after treatment of the tension pneumothorax. Doctors need to evaluate the cardiac findings along with respiratory findings.
In primary care, chest X-rays are commonly performed to assess patients presenting with a prolonged
cough. However, the extent to which the flms are accurately interpreted depends on the skill of the
doctors. Doctors with insufcient experience may miss an exact diagnosis when evaluating a flm,
especially in patients with nonspecifc symptoms, such as in the case discussed in this paper.
( Copied from article ).
Assessing the repeat rate is crucial to reduce unnecessary dose to the patient by identifying the major cause for repeating the x-rays exposure to the patient and apply corrective measures. To analyse the repeat rate of routine lower limb projections in direct digital radiography (DR) from general radiology department of Pantai Klang Hospital. 26 months retrospective repeated radiograph was acquired from Picture Archiving and Communication System (PACS) at Hospital Pantai Klang. The retrieved radiographs were grouped based on the reason for the i radiographs being rejected which are incorrect positioning, incorrect collimation, patient movement, incorrect exposure factors, artefact, and other reasons. Total repeated radiographs retrieved for basic lower limbs projections were 13616. Knee was the highest repeted examination and the lowest repeat rate was tibia fibula. (repeat rate: knee = 1.04%, tibia fibula = 0.57%). incorrect positioning is the major causes for repeat exposure for all examinations type, followed by incorrect collimation, other categories, centring ray error, incorrect exposure factors and artifact.
Nanotechnology is one of the most interesting areas of research due to its flexibility to improve or form new products from nanoparticles (NPs), and as a fast, greener, more eco-friendly and sustainable solution to technological and environmental challenges. Among metal oxides of photocatalytic performance, the use of titania (TiO2) as photocatalyst is most popular due to its unique optical and electronic properties. Despite the wide utilization, the synthesis of TiO2 NPs bears many disadvantages: it utilizes various less environmental-friendly chemicals, high cost, requires high pressure and energy, and potentially hazardous physical and chemical methods. Hence, the development of green synthesis approach with eco-friendly natural products can be used to overcome these adverse effects. In this work, TiO2 NPs have been prepared by using Deinbollia pinnata leaves extracts, obtained by different solvents (n-hexane, ethyl acetate, and ethanol) with different polarities. The extracts acted as the reducing agent, while titanium isopropoxide as the precursor and water as the solvent. X-ray diffraction (XRD) pattern confirmed the synthesized TiO2 consist of anatase phase in high purity, with average crystallite size in the range of 19-21 nm. Characterization by using field emission scanning electron microscopy (FESEM) showed the TiO2 NPs possess a uniform semi-spherical shape in the size range of 33-48 nm. The energy dispersive X-ray (EDX) spectra of green TiO2 NPs showed two peaks for the main elements of Ti (61 Wt.%) and O (35 Wt.%). The band-gap energy of 3.2 eV was determined using UV-Vis spectroscopy. From the nitrogen sorption analysis, type V isotherm of the material was obtained, with BET surface area of 31.77 m2/g. The photocatalytic activity of synthesized TiO2 was evaluated for photodegradation of methyl orange (MO) under UV light irradiation. Based on the results, it is shown that TiO2 NPs synthesized with D. pinnata leaves extracted using ethyl acetate showed the most effective photodegradation performance, achieving 98.7% of MO conversion within 150 min. It can be concluded that the use of plant extracts in synthesis with TiO2 managed to produce highly crystalline anatase TiO2 with superior photocatalytic activity in the photodegradation of organic dye.
In radiography, radiation workers are responsible to protect patients and their caregivers from adverse effects of X-rays during diagnostic procedures. The X-ray examination rooms are designated as controlled areas where only authorised persons are allowed to enter. However, sometimes radiographers allow next in-line patients’ and caregivers in X-ray examination room and ask them to stand behind the mobile lead shielding when exposure is on. The objectives of this study were to determine the amount of scatter radiation dose at different heights with respect to the floor in the X-ray examination room and to educate and increase the awareness of radiation workers about the scattered radiation in minimizing the unnecessary radiation dose to patient’s caregivers. Siemens Multix Top X-ray system was used. Kyoto Kagaku PBU-50 whole body phantom was scanned. The phantom (torso) was positioned for anteroposterior (AP) lumbar projection on the examination table. The nanoDot OSLDs were fixed behind the lead shielding at different heights (120, 130, 140, 150, 160 and 170 cm) with respect to the floor 2.5 meters away from the central ray of X-ray beam. The phantom was exposed using different tube voltages 68 kVp, 79 kVp and 90 kVp at a constant tube current of 32 mAs fixing a 100 cm source to image distance (SID). Scatter radiation doses measured at different heights were different for each exposure. The highest scattered radiation dose measured was 6.4 mGy at 130 cm height for 79 kVp exposure. In conclusion the measured scattered radiation doses were within the acceptable annual dose limits as recommended by NCRP 116 and ICRP 103 for patient caregiver. However, a smallest amount of radiation dose may increase the risk of cancer. Thus, the negligence must not be overlooked because it exposes the caregiver to unnecessary radiation.
Introduction: Melatonin (MEL) loaded alginate-chitosan/beta-tricalcium phosphate (Alg-CH/β-TCP) composite hy- drogel has been formulated as a scaffold for bone regeneration. MEL in the scaffold was anticipated to accelerate bone regeneration. The objective of this study is to observe signs of systemic toxicity and physical changes on surface defected bone for bone regenerative performance of the composite. Methods: The proximal-medial metaphyseal cortex of the left tibia of New Zealand white rabbit was the surgical site of the defect. A total of nine rabbits were randomly allocated to three groups; Group I; implanted with MEL loaded Alg-CH/β-TCP, Group II; Alg-CH/β-TCP and Group III defects were sham control. The rabbits were daily observed to determine systemic toxicity effects by composites. The physical changes to implanted site were observed using digital x-ray radiography and computerized tomography at weeks 0, 2, 4, 6 and 8 of post-implantation. Results: There were no clinical signs of systemic toxicity for all groups of rabbits. Digital radiography did not show adverse effects to the bone. Computerized tomography showed reduction in the area size and depth volume of the implantation site, but accelerated regeneration within the 8 weeks was not significantly different (P
Introduction: Various phantom with varied materials has been proposed to replace the human body. Besides, there is always a demand to use the local material as a phantom material, which is readily available and inexpensive. Wood is usually preferred because it is multifunction, environmentally friendly, low in toxic, inexpensive, as well as easy to use and prepare. Previous studies have found that Rhizophora spp. is a suitable natural source material and has been suggested due to its comparable dosimetric properties to commercial phantom. Methods: In this study, fabricated Rhizophora spp. particleboards phantom was opted as a solid-equivalent phantom medium at low energy photon beams using Gafchromic film x-ray quality assurance 2 (XRQA2). Additionally, the characteristics of XRQA2 film in the diagnostic energy range were generated. Results: Interestingly, the density of the fabricated Rhizophora spp particleboards was observed to have the same density with the water equivalent material (ρ= 1.00 g.cm-3) and has shown to have loosened agreement with PDD of water phantom at approximately 25% of the dose error. Also, further analysis using XRQA 2 film showed that energy was independent at different ranges. Conclusion: The analysis of fabricated Rhizophora spp particleboards undertaken here has extended our knowledge of the possibility of man- ufacturing cost-effective water equivalent phantom by using binder-less particleboard from Rhizophora spp. There- fore, a definite need for smaller interspacing particles should be considered to elevate the potential of Rhizophora spp particle boards as water equivalent materials.
The Malaysian Association of Medical Physics (MAMP) was set up in the year 2000 to promote and further develop the field that was relatively new in Malaysia. The article briefly summarises key developments in medical physics since the first discovery of x-rays in 1895. The resulted rapid progress in the field was also highlighted and related to the pace of development in Malaysia. Key activities organised by MAMP were also addressed. The international practices related to the field and the profession were highlighted and compared to the current status in Malaysia. Although the field has progressed well in the country, there are several gaps identified to further improve the field and the profession in Malaysia.
The aimed of this study is to estimate the entrance surface dose (ESD) of routine chest X-ray (CXR) examination and to compare the direct and indirect measurement. This study also extended to relate with the patients body thickness and established lifetime attributable risk (LAR) of the examinations. A total of 101 CXR examinations in posteroanterior (PA) projections were selected
as subjects and data, such as patient habitus and scanning acquisition parameters were recorded. The mean ESD value obtained from the TLD-100 and the software calculation was 0.31 mGy and 0.17 mGy, respectively. The percentage deviation obtained ranged from 25.5% to 61.3%. In comparison with the national diagnostic reference level (DRL), the mean values of ESD obtained from this study were lower by a factor of 3. Furthermore, it was observed that the mean absorbed dose of the adrenals, kidneys, lungs, oesophagus, and heart walls were lower as compared to the ESD value. The examinations were only associated with very low risk of cancer incidence and mortality. Hence, the results of this study suggested a need for standardisations of the personnel training to perform X-ray examinations according to ALARA principles.
Adenokarsinoma paru-paru miliari adalah sangat jarang dan agresif. Adenokarsinoma paru-paru biasanya menunjukkan sifat ketulan pada peparu yang berkaitan dengan kerosakan paru-paru dan efusi pleura. Adenokarsinoma ini jarang jarang berpunca daripada tapak selain daripada tapak primer, tidak seperti kanser-kanser lain contohnya kanser tiroid, koriokarsinoma dan sarcoma. Kami membentangkan di sini kes seorang suri rumah berusia 50 tahun yang mengadu batuk-batuk, hilang selera makan dan sukar untuk bernafas selama 1 bulan. Perawat perubatan primer telah merawat beliau sebagai jangkitan kuman pada paru-paru. Disebabkan keadaan yang tidak pulih dan semakin melarat, beliau dibawa ke Jabatan Kecemasan. Oksigen beliau dikesan sebanyak 93% atas udara bilik. Berdasarkan sejarah pesakit dan penemuan X-ray paru-paru, rawatan untuk tuberculosis miliari telah di beri walaupun ujian Mantoux dan kahak negatif. Berikutan peningkatan tanda-tanda dan intubasi, bronkoskopi kemudian mendedahkan diagnosis adenokarsinoma paru-paru. Sebagai pelajaran, penampilan miliari radiografi tidak dikelirukan kepada tuberkulosis sahaja, kerana sebab-sebab berbahaya yang lain perlu disiasat. Bronkoskop dengan analisis histopatologi diperlukan, terutamanya jika Mantoux dan sputum adalah negatif.
Penekanan saraf lateral kutaneus femoral merupakan punca kepada penyakit meralgia parestetika. Gejala penyakit ini ialah kesakitan dan perubahan sensori pada bahagian lateral paha. Namun, gejala penyakit ini seakan menyerupai gejala penyakit lain seperti radikulopati lumbar, penyempitan ruang femoro-acetabular, bursitis trokanterik dan beberapa contoh lain. Meralgia parestetika merupakan diagnosis secara pengecualian setelah penyebab kepada kesakitan pada bahagian lateral paha tidak dapat dibuktikan melalui hasil penyiasatan yang terperinci. Pengetahuan anatomi tentang saraf yang mensarafi bahagian paha adalah amat penting untuk mengenalpasti punca kesakitan yang dialami. Kami ingin melaporkan satu kes yang melibatkan seorang pesakit lelaki berumur 46 tahun, telah didiagnos menghidap kencing manis, darah tinggi, masalah jantung yang telah datang ke Jabatan Kecemasan dan Trauma dengan aduan kesakitan akut pada bahagian lateral paha kanan. Kesakitan yang dialami digambarkan sebagai rasa seperti terbakar, dicucuk dan disertai dengan rasa kebas. Selain itu, terdapat pengurangan sensasi rasa pada bahagian paha yang sakit. Tiada aduan berkaitan sakit pada rangsangan ringan (allodinia) atau sakit yang berlebihan pada rangsangan kuat (hiperalgesia). Bacaan gula darah kapilari ialah 8.4 mmol/l dan keputusan HbA1c ialah 7%. Diagnosis meralgia parestetika telah disahkan setelah semua kemungkinan diagnosis lain tidak dapat dibuktikan melalui pemeriksaan fizikal, ujian makmal dan radiologi (x-ray, ultrasound dan MRI). Keadaan pesakit bertambah baik selepas diberikan rawatan ubat secara oral dan menjalani sesi fisioterapi.
The key component in deep learning research is the availability of training data sets. With a limited number of publicly available COVID-19 chest X-ray images, the generalization and robustness of deep learning models to detect COVID-19 cases developed based on these images are questionable. We aimed to use thousands of readily available chest radiograph images with clinical findings associated with COVID-19 as a training data set, mutually exclusive from the images with confirmed COVID-19 cases, which will be used as the testing data set. We used a deep learning model based on the ResNet-101 convolutional neural network architecture, which was pretrained to recognize objects from a million of images and then retrained to detect abnormality in chest X-ray images. The performance of the model in terms of area under the receiver operating curve, sensitivity, specificity, and accuracy was 0.82, 77.3%, 71.8%, and 71.9%, respectively. The strength of this study lies in the use of labels that have a strong clinical association with COVID-19 cases and the use of mutually exclusive publicly available data for training, validation, and testing.
In this work, the optimum filler loading to prepare epoxy/organoclay nanocomposites by the in-situ polymerization method was studied. Bi-functionalized montmorillonite at different filler loading (0.5, 1.0, 2.0, 4.0 wt %) was dispersed in epoxy resin by using a high shear speed homogenizer. The effect on morphology, thermal, dynamic mechanical, and tensile properties of the epoxy/organoclay nanocomposites were studied in this work. Wide-angle X-ray scattering (WAXS) and field emission scanning electron microscope (FESEM) studies revealed that possible intercalated structures were obtained in epoxy/organoclay nanocomposites. Thermogravimetric analysis (TGA) shows that epoxy/organoclay nanocomposites exhibit higher thermal stability at the maximum and final decomposition temperature, as well as higher char content, compared to pristine epoxy. The dynamic mechanical analysis (DMA) indicate that storage modulus (E'), loss modulus (E″), cross-link density and glass transition temperature (Tg) of the nanocomposites were improved with organoclay loading up to 1 wt %. Beyond this loading limit, the deterioration of properties was observed. A similar trend was also observed on tensile strength and modulus. We concluded from this study that organoclay loading up to 1 wt % is suitable for further study to fabricate hybrid nanocomposites for various applications.