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Fulltext Evaluation of an integrated 3D-printed phantom for coronary CT angiography using iterative reconstruction algorithm

Abdullah KA, McEntee MF, Reed W, Kench PL

J Med Radiat Sci, 2020 Sep;67(3):170-176.
PMID: 32219989 DOI: 10.1002/jmrs.387

INTRODUCTION: 3D-printed imaging phantoms are now increasingly available and used for computed tomography (CT) dose optimisation study and image quality analysis. The aim of this study was to evaluate the integrated 3D-printed cardiac insert phantom when evaluating iterative reconstruction (IR) algorithm in coronary CT angiography (CCTA) protocols.
METHODS: The 3D-printed cardiac insert phantom was positioned into a chest phantom and scanned with a 16-slice CT scanner. Acquisitions were performed with CCTA protocols using 120 kVp at four different tube currents, 300, 200, 100 and 50 mA (protocols A, B, C and D, respectively). The image data sets were reconstructed with a filtered back projection (FBP) and three different IR algorithm strengths. The image quality metrics of image noise, signal-noise ratio (SNR) and contrast-noise ratio (CNR) were calculated for each protocol.
RESULTS: Decrease in dose levels has significantly increased the image noise, compared to FBP of protocol A (P

Matched MeSH terms: Printing, Three-Dimensional*
Endoscopic skull base training using 3D printed models with pre-existing pathology

Narayanan V, Narayanan P, Rajagopalan R, Karuppiah R, Rahman ZA, Wormald PJ, et al.

Eur Arch Otorhinolaryngol, 2015 Mar;272(3):753-7.
PMID: 25294050 DOI: 10.1007/s00405-014-3300-3

Endoscopic base of skull surgery has been growing in acceptance in the recent past due to improvements in visualisation and micro instrumentation as well as the surgical maturing of early endoscopic skull base practitioners. Unfortunately, these demanding procedures have a steep learning curve. A physical simulation that is able to reproduce the complex anatomy of the anterior skull base provides very useful means of learning the necessary skills in a safe and effective environment. This paper aims to assess the ease of learning endoscopic skull base exposure and drilling techniques using an anatomically accurate physical model with a pre-existing pathology (i.e., basilar invagination) created from actual patient data. Five models of a patient with platy-basia and basilar invagination were created from the original MRI and CT imaging data of a patient. The models were used as part of a training workshop for ENT surgeons with varying degrees of experience in endoscopic base of skull surgery, from trainees to experienced consultants. The surgeons were given a list of key steps to achieve in exposing and drilling the skull base using the simulation model. They were then asked to list the level of difficulty of learning these steps using the model. The participants found the models suitable for learning registration, navigation and skull base drilling techniques. All participants also found the deep structures to be accurately represented spatially as confirmed by the navigation system. These models allow structured simulation to be conducted in a workshop environment where surgeons and trainees can practice to perform complex procedures in a controlled fashion under the supervision of experts.

Matched MeSH terms: Printing, Three-Dimensional*
Monoclonal Antibody Delivery Using 3D Printed Biobased Hollow μNe3dle Arrays for the Treatment of Osteoporosis

Uddin MJ, Economidou SN, Guiraud L, Kazi M, Alanazi FK, Douroumis D

Mol Pharm, 2024 Sep 02;21(9):4465-4475.
PMID: 39110837 DOI: 10.1021/acs.molpharmaceut.4c00379

Transdermal microneedles have demonstrated promising potential as an alternative to typical drug administration routes for the treatment of various diseases. As microneedles offer lower administration burden with enhanced patient adherence and reduced ecological footprint, there is a need for further exploitation of microneedle devices. One of the main objectives of this work was to initially develop an innovative biobased photocurable resin with high biobased carbon content comprising isobornyl acrylate (IBA) and pentaerythritol tetraacrylate blends (50:50 wt/wt). The optimization of the printing and curing process resulted in μNe3dle arrays with durable mechanical properties and piercing capacity. Another objective of the work was to employ the 3D printed hollow μNe3dles for the treatment of osteoporosis in vivo. The 3D printed μNe3dle arrays were used to administer denosumab (Dmab), a monoclonal antibody, to osteoporotic mice, and the serum concentrations of critical bone minerals were monitored for six months to assess recovery. It was found that the Dmab administered by the 3D printed μNe3dles showed fast in vitro rates and induced an enhanced therapeutic effect in restoring bone-related minerals compared to subcutaneous injections. The findings of this study introduce a novel green approach with a low ecological footprint for 3D printing of biobased μNe3dles, which can be tailored to improve clinical outcomes and patient compliance for chronic diseases.

Matched MeSH terms: Printing, Three-Dimensional*
A randomized comparative study to prevent supine hypotension syndrome in pregnant females undergoing LSCS after giving spinal anesthesia using a wedge and novel 3D printed uterine displacement device

Kaur H, Narayanan L, Yachendra VSG, Bhaskaran B

Med J Malaysia, 2025 Jan;80(Suppl 1):37-43.
PMID: 39773941

INTRODUCTION: Pregnancy induces physiological changes, including alterations in cardiovascular dynamics, predisposing pregnant women to supine hypotension syndrome (SHS) during lower-segment cesarean section (LSCS) under spinal anesthesia. Various methods, including manual displacement of the uterus and use of wedges or cushions, have been proposed to prevent SHS, but their effectiveness remains variable. This study aimed to compare the efficacy of a novel 3D-printed uterine displacement device with that of a traditional wedge in preventing SHS during LSCS after spinal anesthesia.
METHODOLOGY: This prospective, randomized, controlled trial enrolled pregnant females undergoing LSCS after spinal anesthesia. The participants were randomized into two groups: a novel 3D device group and a traditional wedge group. Primary outcome measures included the incidence of SHS, while secondary outcomes included maternal hemodynamic parameters, fetal outcomes, feasibility, ease of use, and the safety profile of the devices.
RESULTS: Baseline characteristics were well balanced between the two groups. Although some differences in maternal hemodynamic parameters were noted, the incidence of SHS was significantly lower in the novel 3D device group than that in the traditional wedge group. Fetal outcomes did not differ significantly between the groups. The novel 3D device demonstrated high compatibility with various patient anatomies and was easy to integrate into routine practice. The adverse event profiles were similar between the groups.
CONCLUSION: This study highlights the potential of a novel 3D-printed uterine displacement device for preventing SHS during LSCS, thereby improving maternal and fetal outcomes. Future research should further validate these findings and explore the long-term implications of the maternal and neonatal outcomes.

Matched MeSH terms: Printing, Three-Dimensional*
3D-printed poly(ethylene) glycol diacrylate (PEGDA)-chitosan-nanohydroxyapatite scaffolds: Structural characterization and cellular response

Ngau SM, Cheah KH, Wong VL, Khiew PS, Lim SS

Int J Biol Macromol, 2025 Mar;296:139652.
PMID: 39793825 DOI: 10.1016/j.ijbiomac.2025.139652

Polymer-based scaffolds with bioactive materials offer great potential in bone tissue engineering. Polyethylene glycol diacrylate (PEGDA) scaffolds fabricated via liquid crystal display 3D printing technique lack inherent osteoconductivity. To improve such properties, chitosan of 10 and 20 wt% and nanohydroxyapatite (nHA) (3-10 wt%) were incorporated into PEGDA scaffolds. nHA, synthesized via wet chemical precipitation, had a particle size of 28 nm and exhibited low crystallinity, as confirmed by X-ray diffraction. PEGDA-chitosan-nHA scaffolds underwent post-curing and 70 % ethanol leaching treatment. The presence of chitosan and nHA in the composite scaffolds was confirmed by their characteristic peaks. TGA analyses further verified nHA content correlating to the intended amount. The scaffolds featured interconnected pores ranging from 2891 to 3382 μm and porosities between 35 and 56 %. The swelling percentage and compressive modulus were reported at ~71-93 % and 0.52-1.18 MPa, respectively. Notably, PEGDA-chitosan-nHA scaffolds showed enhanced in vitro efficacy than pure PEGDA scaffolds, by promoting better MG63 cell adhesion (p

Matched MeSH terms: Printing, Three-Dimensional*
Fulltext Effect of Printing Parameters on Tensile, Dynamic Mechanical, and Thermoelectric Properties of FDM 3D Printed CABS/ZnO Composites

Aw YY, Yeoh CK, Idris MA, Teh PL, Hamzah KA, Sazali SA

Materials (Basel), 2018 Mar 22;11(4).
PMID: 29565286 DOI: 10.3390/ma11040466

Fused deposition modelling (FDM) has been widely used in medical appliances, automobile, aircraft and aerospace, household appliances, toys, and many other fields. The ease of processing, low cost and high flexibility of FDM technique are strong advantages compared to other techniques for thermoelectric polymer composite fabrication. This research work focuses on the effect of two crucial printing parameters (infill density and printing pattern) on the tensile, dynamic mechanical, and thermoelectric properties of conductive acrylonitrile butadiene styrene/zinc oxide (CABS/ZnO composites fabricated by FDM technique. Results revealed significant improvement in tensile strength and Young's modulus, with a decrease in elongation at break with infill density. Improvement in dynamic storage modulus was observed when infill density changed from 50% to 100%. However, the loss modulus and damping factor reduced gradually. The increase of thermal conductivity was relatively smaller compared to the improvement of electrical conductivity and Seebeck coefficient, therefore, the calculated figure of merit (ZT) value increased with infill density. Line pattern performed better than rectilinear, especially in tensile properties and electrical conductivity. From the results obtained, FDM-fabricated CABS/ZnO showed much potential as a promising candidate for thermoelectric application.

Matched MeSH terms: Printing
Fulltext Three-Dimensional Printed Electrode and Its Novel Applications in Electronic Devices

Foo CY, Lim HN, Mahdi MA, Wahid MH, Huang NM

Sci Rep, 2018 May 09;8(1):7399.
PMID: 29743664 DOI: 10.1038/s41598-018-25861-3

Three-dimensional (3D) printing technology provides a novel approach to material fabrication for various applications because of its ability to create low-cost 3D printed platforms. In this study, a printable graphene-based conductive filament was employed to create a range of 3D printed electrodes (3DEs) using a commercial 3D printer. This printing technology provides a simplistic and low-cost approach, which eliminates the need for the ex-situ modification and post-treatment of the product. The conductive nature of the 3DEs provides numerous deposition platforms for electrochemical active nanomaterials such as graphene, polypyrrole, and cadmium sulfide, either through electrochemical or physical approaches. To provide proof-of-concept, these 3DEs were physiochemically and electrochemically evaluated and proficiently fabricated into a supercapacitor and photoelectrochemical sensor. The as-fabricated supercapacitor provided a good capacitance performance, with a specific capacitance of 98.37 Fg-1. In addition, these 3DEs were fabricated into a photoelectrochemical sensing platform. They had a photocurrent response that exceeded expectations (~724.1 μA) and a lower detection limit (0.05 μM) than an ITO/FTO glass electrode. By subsequently modifying the printing material and electrode architecture, this 3D printing approach could provide a facile and rapid manufacturing process for energy devices based on the conceptual design.

Matched MeSH terms: Printing, Three-Dimensional
Fulltext Advances and Future Perspectives in 4D Bioprinting

Ashammakhi N, Ahadian S, Zengjie F, Suthiwanich K, Lorestani F, Orive G, et al.

Biotechnol J, 2018 Dec;13(12):e1800148.
PMID: 30221837 DOI: 10.1002/biot.201800148

Three-dimensionally printed constructs are static and do not recapitulate the dynamic nature of tissues. Four-dimensional (4D) bioprinting has emerged to include conformational changes in printed structures in a predetermined fashion using stimuli-responsive biomaterials and/or cells. The ability to make such dynamic constructs would enable an individual to fabricate tissue structures that can undergo morphological changes. Furthermore, other fields (bioactuation, biorobotics, and biosensing) will benefit from developments in 4D bioprinting. Here, the authors discuss stimuli-responsive biomaterials as potential bioinks for 4D bioprinting. Natural cell forces can also be incorporated into 4D bioprinted structures. The authors introduce mathematical modeling to predict the transition and final state of 4D printed constructs. Different potential applications of 4D bioprinting are also described. Finally, the authors highlight future perspectives for this emerging technology in biomedicine.

Matched MeSH terms: Printing, Three-Dimensional
Low-cost low-tech obstacle pushing/gliding wheelchair accessory

Jalal Abdullah S, Shaikh Mohammed J

Disabil Rehabil Assist Technol, 2019 11;14(8):849-858.
PMID: 30556753 DOI: 10.1080/17483107.2018.1539130

Purpose: Some wheelchair users continue to struggle in maneuvering a wheelchair and navigating through manual doors. Several smart wheelchairs and robotic manipulators were developed to minimize such challenges facing disabled people. Disappointingly, a majority of these high-tech solutions are restricted to laboratories and are not extensively available as commercial products. Previously, a low-tech wheelchair accessory (arc-shaped with many wheels) for pushing doors was modelled and simulated. This work demonstrates the fabrication and testing of the first-generation prototype of the accessory.Materials and methods: The accessory has side portions with a straight arrangement of wheels and a front portion with a straight-arc-straight arrangement of wheels. The accessory was fabricated using conventional manufacturing, off-the-shelf components, and 3D printed ABS fasteners. Stress analysis simulations were done for the fasteners that attach the front accessory to the wheelchair frame. The proof-of-concept of the prototype installed onto a powered wheelchair was tested with a door and an obstacle, each with ∼50 N resistance force.Results: Prototype tests demonstrate the ability of the accessory along with the mechanical robustness of the 3D printed fasteners to push open doors allowing easy navigation through doors and to push/glide against obstacles. The accessory is foldable and detachable.Conclusion: The low-cost of the accessory makes it affordable to many users intending to improve their quality of life. The current study provides an engineering perspective of the accessory, and a clinical perspective is crucial. Other potential applications of the wheelchair accessory include use with scooters, walkers and stretchers.Implications for rehabilitationLow-cost, low-tech accessory is foldable and detachable.Accessory is effective for pushing doors and pushing/gliding against obstacles.Protective nature of the front accessory could prove highly beneficial to some wheelchair users.

Matched MeSH terms: Printing, Three-Dimensional
Fulltext In Situ Controlled Surface Microstructure of 3D Printed Ti Alloy to Promote Its Osteointegration

Shan L, Kadhum AAH, Al-Furjan MSH, Weng W, Gong Y, Cheng K, et al.

Materials (Basel), 2019 Mar 10;12(5).
PMID: 30857349 DOI: 10.3390/ma12050815

It is well known that three-dimensional (3D) printing is an emerging technology used to produce customized implants and surface characteristics of implants, strongly deciding their osseointegration ability. In this study, Ti alloy microspheres were printed under selected rational printing parameters in order to tailor the surface micro-characteristics of the printed implants during additive manufacturing by an in situ, controlled way. The laser path and hatching space were responsible for the appearance of the stripy structure (S), while the bulbous structure (B) and bulbous⁻stripy composite surface (BS) were determined by contour scanning. A nano-sized structure could be superposed by hydrothermal treatment. The cytocompatibility was evaluated by culturing Mouse calvaria-derived preosteoblastic cells (MC3T3-E1). The results showed that three typical microstructured surfaces, S, B, and BS, could be achieved by varying the 3D printing parameters. Moreover, the osteogenic differentiation potential of the S, B, and BS surfaces could be significantly enhanced, and the addition of nano-sized structures could be further improved. The BS surface with nano-sized structure demonstrated the optimum osteogenic differentiation potential. The present research demonstrated an in situ, controlled way to tailor and optimize the surface structures in micro-size during the 3D printing process for an implant with higher osseointegration ability.

Matched MeSH terms: Printing, Three-Dimensional
Patient-Specific Reconstruction Utilizing Computer Assisted 3D Modelling for Partial Bone Flap Defect in Hybrid Cranioplasty

Low PH, Abdullah JY, Abdullah AM, Yahya S, Idris Z, Mohamad D

J Craniofac Surg, 2019 Jun 28.
PMID: 31261343 DOI: 10.1097/SCS.0000000000005713

PURPOSE: Decompressive craniectomy is a life-saving procedure in the setting of malignant brain swelling. Patients who survive require cranioplasty for anatomical reconstruction and cerebral protection. Autologous cranioplasty remains the commonest practice nowadays, but partial bone flap defects are frequently encountered. The authors, therefore, seek to develop a new technique of reconstruction for cranioplasty candidate with partial bone flap defect utilizing computer-assisted 3D modeling and printing.
METHODS: A prospective study was conducted to evaluate the outcome of a new reconstruction technique that produces patient-specific hybrid polymethyl methacrylate-autologous cranial implant. Computer-assisted 3D modeling and printing was utilized to produce patient-specific molds, which allowed real-time reconstruction of bone flap with partial defect intra-operatively.
RESULTS: Outcome assessment for 11 patients at 6 weeks and 3 months post-operatively revealed satisfactory implant alignment with favorable cosmesis. The mean visual analog scale for cosmesis was 91. Mean implant size was 50cm, and the mean duration of intra-operative reconstruction was 30 minutes. All of them revealed improvement in quality of life following surgery as measured by the SF-36 score. Cost analysis revealed that this technique is more cost-effective compared to customized cranial prosthesis.
CONCLUSION: This new technique and approach produce hybrid autologous-alloplastic bone flap that resulted in satisfactory implant alignment and favorable cosmetic outcome with relatively low costs.

Matched MeSH terms: Printing
Fulltext An Improved Fabrication Technique for the 3-D Frequency Selective Surface based on Water Transfer Printing Technology

Harnois M, Himdi M, Yong WY, Rahim SKA, Tekkouk K, Cheval N

Sci Rep, 2020 Feb 03;10(1):1714.
PMID: 32015444 DOI: 10.1038/s41598-020-58657-5

Manufacturing an array of high-quality metallic pattern layers on a dielectric substrate remains a major challenge in the development of flexible and 3-D frequency selective surfaces (FSS). This paper proposes an improved fabrication solution for the 3-D FSS based on water transfer printing (WTP) technology. The main advantages of the proposed solution are its ability to transform complicated 2-D planar FSS patterns into 3-D structures while improving both manufacturing quality and production costs. WTP technology makes use of water surface tension to keep the thin metallic patterns of the proposed FSS floating flat with the absence of a solid planar substrate. This feature enables these metallic FSS patterns to be transferred onto 3-D structures through a dipping process. To test the effectiveness of the proposed technique, the FSS was designed using computer simulation software Microwave Studio to obtain the numerical performance of the FSS structure. The WTP technology was then used to fabricate the proposed FSS prototype before its performance was tested experimentally. The measurement results agreed well with the numerical results, indicating the proposed manufacturing solution would support the development of complicated 3-D electronics devices, such as conformal antenna arrays and metamaterials.

Matched MeSH terms: Printing, Three-Dimensional
Fulltext Development of patient-specific 3D-printed breast phantom using silicone and peanut oils for magnetic resonance imaging

Sindi R, Wong YH, Yeong CH, Sun Z

Quant Imaging Med Surg, 2020 Jun;10(6):1237-1248.
PMID: 32550133 DOI: 10.21037/qims-20-251

Background: Despite increasing reports of 3D printing in medical applications, the use of 3D printing in breast imaging is limited, thus, personalized 3D-printed breast model could be a novel approach to overcome current limitations in utilizing breast magnetic resonance imaging (MRI) for quantitative assessment of breast density. The aim of this study is to develop a patient-specific 3D-printed breast phantom and to identify the most appropriate materials for simulating the MR imaging characteristics of fibroglandular and adipose tissues.
Methods: A patient-specific 3D-printed breast model was generated using 3D-printing techniques for the construction of the hollow skin and fibroglandular region shells. Then, the T1 relaxation times of the five selected materials (agarose gel, silicone rubber with/without fish oil, silicone oil, and peanut oil) were measured on a 3T MRI system to determine the appropriate ones to represent the MR imaging characteristics of fibroglandular and adipose tissues. Results were then compared to the reference values of T1 relaxation times of the corresponding tissues: 1,324.42±167.63 and 449.27±26.09 ms, respectively. Finally, the materials that matched the T1 relaxation times of the respective tissues were used to fill the 3D-printed hollow breast shells.
Results: The silicone and peanut oils were found to closely resemble the T1 relaxation times and imaging characteristics of these two tissues, which are 1,515.8±105.5 and 405.4±15.1 ms, respectively. The agarose gel with different concentrations, ranging from 0.5 to 2.5 wt%, was found to have the longest T1 relaxation times.
Conclusions: A patient-specific 3D-printed breast phantom was successfully designed and constructed using silicone and peanut oils to simulate the MR imaging characteristics of fibroglandular and adipose tissues. The phantom can be used to investigate different MR breast imaging protocols for the quantitative assessment of breast density.

Matched MeSH terms: Printing, Three-Dimensional
Fulltext Design and development of 3d face mask clips for hijab

Ahmad Sofian, Shminan, Rehman, Ullah Khan, Wan Norizan, Wan Hashim, Iswandy, Jamaludin

Journal of Cognitive Sciences & Human Development, 2020;6(2):52-62.
MyJurnal

The world has suffered from a critical shortage of Personal Protective Equipment (PPE) (Riva et al., 2007) during the pandemic of Covid-19 for medical staffs, the front liners. Like the whole world, Malaysia also imposed the stay-at-home and Movement Control Order (MCO) to break the chain of infections and flatten the curve of cases. The supply of PPE became a challenge during the lock down. There have been joined efforts from various parties stepping up, with different ways to help the production process of these key equipment but mostly focus on PPTs for male. Another challenge was face mask for Muslim lady health workers who wear hijab. This paper is about how to overcome these challenges and designed a novel face mask clip for hijab, using 3D printing. The face mask clip is for wearing a mask over hijab and is designed by generating a 3D digital file using computer-aided design (Hourcade, Bullock-Rest, & Hansen, 2012) software. Then the 3D design was converted to Standard Tessellation Language (STL) format, for the use of 3D printing systems. Then the design was split into layers for precise printing. The clips were tested by the staff in faculty of Cognitive Sciences and Human Development, Universiti Malaysia Sarawak. Feedbacks were collected by an online survey using the modified System Usability Scale. The participants reported that the clips are very comfortable and easy to use.

Matched MeSH terms: Printing, Three-Dimensional
Deviation of dental implants placed using a novel 3D-printed surgical guide: An in vitro study

Etajuri EA, Suliman E, Mahmood WAA, Ibrahim N, Buzayan M, Mohd NR

Dent Med Probl, 2021 1 16;57(4):359-362.
PMID: 33448161 DOI: 10.17219/dmp/123976

BACKGROUND: There is very little literature available on the reliability of the rapid prototyping technology in the production of three-dimension (3D)-printed surgical guides for accurate implant placement.
OBJECTIVES: The aim of the study was to evaluate the deviation of implant placement performed with a surgical guide fabricated by means of the rapid prototyping technique (the PolyJet™ technology).
MATERIAL AND METHODS: Twenty sheep mandibles were used in the study. Pre-surgical cone-beam computed tomography (CBCT) scans were acquired for the mandibles by using the Kodak 9000 3D cone-beam system. Two implants with dimensions of 4 mm in diameter and 10 mm in length were virtually planned on the 3D models of each mandible by using the Mimics software, v. 16.0. Twenty surgical guides were designed and printed using the PolyJet technology. A total of 40 implants were placed using the surgical guides, 1 on each side of the mandible (2 implants per mandible). The post-surgical CBCT scans of the mandibles were performed and superimposed on the pre-surgical CBCT scans. The amount of deviation between the virtually planned placement and the actual implant placement was measured, and a descriptive analysis was done.
RESULTS: The results showed that the mean deviation at the implant coronal position was 1.82 ±0.74 mm, the mean deviation at the implant apex was 1.54 ±0.88 mm, the mean depth deviation was 0.44 ±0.32 mm, and the mean angular deviation was 3.01 ±1.98°.
CONCLUSIONS: The deviation of dental implant placement performed with a 3D-printed surgical guide (the PolyJet technology) is within the acceptable 2-millimeter limit reported in the literature.

Matched MeSH terms: Printing, Three-Dimensional
Screening of lead exposure among workers in Selangor and Federal Territory in Malaysia

Surif S, Chai CY

Environ Pollut, 1995;88(2):177-81.
PMID: 15091558

The study of lead exposure among workers in Selangor and the Federal Territory was carried out based on the delta-aminolevulinic acid (ALA) level in urine. Occupations which are expected to have higher lead exposure were chosen in this research. The ALA level in the workers' urine was linked to a few variables which may contribute to the lead level in the body. The result of this study showed that the ALA level of the urine of university students (0.352 +/- 0.038 mg/100 ml) < clerical staff (0.560 +/- 0.043 mg/100 ml) < traffic police (0.612 +/- 0.064 mg/100 ml) < vehicle workshop workers (0.673 +/- 0.099 mg/100 ml) < petrol kiosk workers (0.717 +/- 0.069 mg/100 ml) < bus drivers/conductors (0.850 +/- 0.055 mg/100 ml) which was similar to workers in the printing industry (0.852 +/- 0.110 mg/100 ml). The ALA levels in the urine of the exposed workers were significantly different from the control group (university students). However, results obtained from clerical staff revealed that they were also in the exposed group category. Analysis of variance showed that the exposed groups are in a population which is different from the control population. Correlation tests suggest that there is no significant connection between the ALA level in the urine and the variables tested. Furthermore, Duncan's Multiple Range Test showed no significant differences between the smoking/non smoking group, alcoholic/non-alcoholic group, race and sex (p > 0.05).

Matched MeSH terms: Printing
Evaluation of Enzymatic Deinking of Non-impact Ink Laser-Printed Paper Using Crude Enzyme from Penicillium rolfsii c3-2(1) IBRL

Lee KC, Tong WY, Ibrahim D, Arai T, Murata Y, Mori Y, et al.

Appl Biochem Biotechnol, 2017 Jan;181(1):451-463.
PMID: 27596245 DOI: 10.1007/s12010-016-2223-4

Application of microbial enzymes for paper deinking is getting tremendous attention due to the rapidly increasing of waste paper every year. This study reports the deinking efficiency of laser-printed paper by the lignocellulolytic enzyme from Penicillium rolfsii c3-2(1) IBRL strain compared to other enzyme sources as well as commercial available enzymes. High enzymatic deinking efficiency of approximately 82 % on laser-printed paper was obtained by pulp treatment with crude enzyme from P. rolfsii c3-2(1) IBRL. However, this crude enzyme was found to reduce the paper strength properties of the pulp based on the results of tensile, tear and burst indices, most probably due to the cellulose degradation. This was further proven by the low viscosity of paper pulp obtained after enzymatic treatment and increasing of sugar production during the treatment. Balancing to this detrimental effect on paper pulp, high deinking efficiency was achieved within a short period of time, in which the enzymatic treatment was conducted for 30 min that enabled contribution to higher brightness index obtained, thus promoting savings of time and energy consumption, therefore environmental sustainability. Extensive research should be conducted to understand the nature and mechanism of enzymatic deinking process by the crude enzyme from P. rolfsii c3-2(1) IBRL in order to improve paper strength properties.

Matched MeSH terms: Printing
Three-dimensional surgical contouring of craniofacial fibrous dysplasia via patient-specific cutting guides and depth screws

Rengarajoo J, Syed Husman SI, Hariri F

Br J Oral Maxillofac Surg, 2021 09;59(7):843-844.
PMID: 34210576 DOI: 10.1016/j.bjoms.2020.09.028
Matched MeSH terms: Printing, Three-Dimensional
Fulltext Enhancing the Permeate Flux of Direct Contact Membrane Distillation Modules with Inserting 3D Printing Turbulence Promoters

Chang H, Ho CD, Chen YH, Chen L, Hsu TH, Lim JW, et al.

Membranes (Basel), 2021 Apr 07;11(4).
PMID: 33916991 DOI: 10.3390/membranes11040266

Two geometric shape turbulence promoters (circular and square of same areas) of different array patterns using three-dimensional (3D) printing technology were designed for direct contact membrane distillation (DCMD) modules in the present study. The DCMD device was performed at middle temperature operation (about 45 °C to 60 °C) of hot inlet saline water associated with a constant temperature of inlet cold stream. Attempts to reduce the disadvantageous temperature polarization effect were made inserting the 3D turbulence promoters to promote both the mass and heat transfer characteristics in improving pure water productivity. The additive manufacturing 3D turbulence promoters acting as eddy promoters could not only strengthen the membrane stability by preventing vibration but also enhance the permeate flux with lessening temperature polarization effect. Therefore, the 3D turbulence promoters were individually inserted into the flow channel of the DCMD device to create vortices in the flow stream and increase turbulent intensity. The modeling equations for predicting the permeate flux in DCMD modules by inserting the manufacturing 3D turbulence promoter were investigated theoretically and experimentally. The effects of the operating conditions under various geometric shapes and array patterns of turbulence promoters on the permeate flux with hot inlet saline temperatures and flow rates as parameters were studied. The distributions of the fluid velocities were examined using computational fluid dynamics (CFD). Experimental study has demonstrated a great potential to significantly accomplish permeate flux enhancement in such new design of the DCMD system. The permeate flux enhancement for the DCMD module by inserting 3D turbulence promoters in the flow channel could provide a maximum relative increment of up to 61.7% as compared to that in the empty channel device. The temperature polarization coefficient (τtemp) was found in this study for various geometric shapes and flow patterns. A larger τtemp value (the less thermal resistance) was achieved in the countercurrent-flow operation than that in the concurrent-flow operation. An optimal design of the module with inserting turbulence promoters was also delineated when considering both permeate flux enhancement and energy utilization effectiveness.

Matched MeSH terms: Printing, Three-Dimensional
Fulltext Synergistic Effect of Static Magnetic Fields and 3D-Printed Iron-Oxide-Nanoparticle-Containing Calcium Silicate/Poly-ε-Caprolactone Scaffolds for Bone Tissue Engineering

Kao CY, Lin TL, Lin YH, Lee AK, Ng SY, Huang TH, et al.

Cells, 2022 Dec 08;11(24).
PMID: 36552731 DOI: 10.3390/cells11243967

In scaffold-regulated bone regeneration, most three-dimensional (3D)-printed scaffolds do not provide physical stimulation to stem cells. In this study, a magnetic scaffold was fabricated using fused deposition modeling with calcium silicate (CS), iron oxide nanoparticles (Fe3O4), and poly-ε-caprolactone (PCL) as the matrix for internal magnetic sources. A static magnetic field was used as an external magnetic source. It was observed that 5% Fe3O4 provided a favorable combination of compressive strength (9.6 ± 0.9 MPa) and degradation rate (21.6 ± 1.9% for four weeks). Furthermore, the Fe3O4-containing scaffold increased in vitro bioactivity and Wharton's jelly mesenchymal stem cells' (WJMSCs) adhesion. Moreover, it was shown that the Fe3O4-containing scaffold enhanced WJMSCs' proliferation, alkaline phosphatase activity, and the osteogenic-related proteins of the scaffold. Under the synergistic effect of the static magnetic field, the CS scaffold containing Fe3O4 can not only enhance cell activity but also stimulate the simultaneous secretion of collagen I and osteocalcin. Overall, our results demonstrated that Fe3O4-containing CS/PCL scaffolds could be fabricated three dimensionally and combined with a static magnetic field to affect cell behaviors, potentially increasing the likelihood of clinical applications for bone tissue engineering.

Matched MeSH terms: Printing, Three-Dimensional

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