The Influence of Different Aggregates on the Physico-Mechanical Performance of Alkali-Activated Geopolymer Composites Produced Using Romanian Fly Ash

In light of the urgent need to develop environmentally friendly materials that, at some point, will allow the reduction of concrete and, consequently, cement consumption-while at the same time allowing the reuse of waste and industrial by-products-alkali-activated fly ash (AAFA) geopolymer composite emerges as a material of great interest. The aim of this study was to investigate the physico-mechanical performance of composites based on AAFA binders and the effect of different types of aggregates on these properties. The experimental results indicate variations in flexural and compressive strength, which are influenced both by the nature and particle size distribution of aggregates and the binder-to-aggregate ratio. The analysis of the samples highlighted changes in porosity, both in distribution and pore size, depending on the nature of the aggregates. This supports the evolution of physico-mechanical performance indicators.

Preparation of Fe@Fe3O4/ZnFe2O4 Powders and Their Consolidation via Hybrid Cold-Sintering/Spark Plasma-Sintering

Our study is focused on optimizing the synthesis conditions for the in situ oxidation of Fe particles to produce Fe@Fe3O4 core-shell powder and preparation via co-precipitation of ZnFe2O4 nanoparticles to produce Fe@Fe3O4/ZnFe2O4 soft magnetic composites (SMC) through a hybrid cold-sintering/spark plasma-sintering technique. XRD and FTIR measurements confirmed the formation of a nanocrystalline oxide layer on the surface of Fe powder and the nanosized nature of ZnFe2O4 nanoparticles. SEM-EDX investigations revealed that the oxidic phase of our composite was distributed on the surface of the Fe particles, forming a quasi-continuous matrix. The DC magnetic characteristics of the composite compact revealed a saturation induction of 0.8 T, coercivity of 590 A/m, and maximum relative permeability of 156. AC magnetic characterization indicated that for frequencies higher than 1 kHz and induction of 0.1 T, interparticle eddy current losses dominated due to ineffective electrical insulation between neighboring particles in the composite compact. Nevertheless, the magnetic characteristics obtained in both DC and AC magnetization regimes were comparable to those reported for cold-sintered Fe-based SMCs.

Morphological Analyses of W/Cu Functional Graded Materials Obtained by Conventional and Spark Plasma Sintering

The paper presents the analysis of two compaction methods for obtaining W/Cu Functional Graded Materials (FGMs) consisting of three layers with the following compositions (% weight): first layer 80 W/20 Cu, second layer 75 W/25 Cu, and third layer 65 W/35 Cu. Each layer composition was obtained using powders obtained through mechanical milling. The two compaction methods were Spark Plasma Sintering (SPS) and Conventional Sintering (CS). The samples obtained after the SPS and CS were investigated from morphological (scanning electron microscopy-SEM) and compositional (energy dispersive X-ray spectroscopy-EDX) points of views. Additionally, the porosities and the densities of each layer in both cases were studied. It was found that the densities of the sample's layers obtained through SPS are superior to those obtained through CS. The research emphasizes that, from a morphological point of view, the SPS process is recommended for W/Cu-FGMs, having raw materials as fine-graded powders against the CS process.

Heat Treatment and Dynamic Mechanical Analysis Strain Sweep Effects on the Phase Structure and Morphology of an Fe-28Mn-6Si-5Cr Shape Memory Alloy

Fe-Mn-Si-based shape memory alloys (SMAs) have been extensively investigated since 1982 for various useful properties that enhance the development of different applications such as anti-seismic dampers for very tall buildings, pipe joints, or rail fasteners. In particular, the Fe-28Mn-6Si-5Cr (mass. %) alloy has been mainly used in vibration mitigation or self-adjustable axial displacement applications. Dynamic mechanical analysis (DMA), performed by strain sweeps (SS), enables the monitoring of the evolution of storage modulus and internal friction variations with increasing strain amplitudes at different constant frequencies and temperatures. Thus, applying dynamic bending with various frequencies and amplitudes that actually represents an isothermal mechanical treatment. In the present paper, an Fe-28Mn-6 Si-5Cr (mass. %) SMA was cast by ingot metallurgy, hot-rolled, and water quenched in order to obtain thermally induced martensite and avoid the occurrence of cooling cracks. The influence of the holding time, between 2 and 10 h, at 1050 °C and the effects of DMA-SS performed at three different frequencies were analyzed by a differential scanning calorimetry, an X-ray diffraction, and a scanning electron and atomic force microscopy. The effects of the holding time and mechanical treatment on the structure and morphology of martensite plates were corroborated with the results of the thermal analysis.

Frequency Properties of Polymer Bonded Compacts Obtained from Ball Milled Permalloy Powders with Mo and Cu Additions

Nanocrystalline powders from the Permalloy family, Ni₇₅Fe₂₅, Ni₇₉Fe₁₆Mo₅, and Ni₇₇Fe₁₄Cu₅Mo₄, were obtained by mechanical alloying starting from elemental powders. All compositions were milled for up to 24 h in a high-energy planetary ball mill. The powders were single phase and nanocrystalline as determined by X-ray diffraction studies, with larger flatted particle sizes for Ni₇₅Fe₂₅ (about 400 μm) and Ni₇₇Fe₁₄Cu₅Mo₄ (about 470 μm), and smaller particle sizes for Ni₇₉Fe₁₆Mo₅ (about 170 μm). The homogeneity of the samples was verified by energy-dispersive X-ray spectroscopy (EDX). Soft magnetic composites were obtained by adding 3% of Araldite to the powders, followed by compaction at 700 MPa, and then polymerization. A very good powder covering by the polymer layer was proven by EDX elementals maps. The influence of composition change on the electrical resistivity of the compacts was studied. Hysteresis measurements in static and dynamic fields of up to 10 kHz were recorded, showing the influence of composition and particle size on the compact properties.

Producing Soft Magnetic Composites by Spark Plasma Sintering of Pseudo Core-Shell Ni-Fe Alloy@Mn0.5Zn0.5Fe2O4 Powders

Soft magnetic composite (SMC) cores have been obtained by Spark Plasma Sintering (SPS) using pseudo core-shell powders. Pseudo core-shell powders are formed by a core of soft magnetic particle (nanocrystalline permalloy or supermalloy) surrounded by a thin layer (shell) of nanosized soft ferrite (Mn_0.5Zn_0.5Fe₂O₄). Three compositions of pseudo core-shell powders were prepared, with 1, 2 and 3 wt.% of manganese-zinc mixt ferrite. The pseudo core-shell powders were compacted by SPS at temperatures between 500 and 700 °C, with a holding time ranging from 0 to 10 min. Several techniques have been used for characterization of the samples, both, powders and compacts X-ray diffraction (XRD, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), magnetic hysteresis measurements (DC and AC) and electrical resistivity. The electrical resistivity is in the order of 1 × 10^-2 Ωm, 3-4 orders of magnitude higher than supermalloy electrical resistivity. The SPS at lower temperatures (500 °C) conserves the initial phases of the composite, but increasing the sintering temperature and/or sintering time produces a solid-state reaction between the alloy and ferrite phases, with negative consequence on the magnetic properties of the compacts. The initial relative permeability is around 40 and remains constant until to 2000 Hz. The power losses are lower than 2 W/kg until to 2000 Hz.

Structural, Chemical and Magnetic Characterization of Quartz Sand from Cluj Area, Romania for Future Beneficiation in the Glass Industry

For use in crystal glass production, quartz sand must contain less than 0.09% iron. If the sand contains more than 0.09% Fe, the iron must be removed. In the present study, quartz sand from tailings ponds near the Cluj area of Romania is analyzed for potential use in the glass industry, after magnetic separation. The particle size distribution of raw sand was determined, and mineralogical analyses was realized. Using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX), morphology and elemental distribution maps on the particle was performed. The evolution of the iron content versus the particle size was analyzed. Using X-ray diffraction, the phases occurring in the sand were investigated in relation to the particle size. Magnetic separation with two magnets, having different energy, was performed for identifying the phases attached to the magnetic particles. Magnetic hysteresis measurements evidenced complex and multiple iron phase behavior.

Studies on Hot-Rolling Bonding of the Al-Cu Bimetallic Composite

Through the approaches in this article, an attempt was made to analyze the bonding of Al-Cu bimetallic composite layers and the highlight of the diffusion at the boundary between the layers, by hot rolling. An aluminum alloy 6060 plate (EN-AW AlMgSi) and a Cu-ETP ½ hard (CW004A) plate were used. All of these layers of materials were TIG-welded, at both ends, into a heat-treated layered composite and subsequently subjected to the hot-rolling process. The Al-Cu composite material obtained was analyzed by scanning electronic microscopy (SEM) analysis, after being subjected to the tensile test, as well as energy-dispersive X-ray (EDX) analysis. The obtained results highlighted the diffusion at the boundary between the layers of the Al-Cu composite as well as its ductile breakage and the distribution of the amount of Al and Cu at the interface of the layers.

Spark Plasma Sintered Soft Magnetic Composite Based on Fe-Si-Al Surface Oxidized Powders

Soft magnetic composites (SMCs) need a stable matrix to apply heat treatments for enhancing their magnetic characteristics. A stable matrix can be offered by alumina, but the densification of the ferromagnetic particles covered by this oxide (by sintering) can be very difficult. This paper proposes a feasible synthesis route for obtaining alumina matrix SMCs. An Fe-Si-Al alloy with nominal composition Fe85Si9Al6 was obtained by mechanical alloying of elemental Fe, Si, and Al powders, and further, the as-milled powders were superficially oxidized by immersion in HCl solution. The oxide layer was composed of iron, silicon, and aluminum oxides, as the Fourier-transform infrared spectroscopy technique revealed. The Fe-Si-Al@oxide powder was densified by the spark plasma sintering technique-SPS. Upon sintering, a continuous matrix of oxide (mainly alumina) was formed by the reaction of the Fe-Si-Al powder coreswith their oxide layer. The main part of the composite compacts after sintering consisted of an Fe₃Si-ordered phase dispersed in an oxide matrix. The DC and AC tests of magnetic composite compacts showed that upon increasing the sintering temperature, the density, magnetic induction, and magnetic permeability increased. The initial magnetic permeability was constant in the entire range of testing frequencies and the magnetic losses increased linearly. The stability of the magnetic characteristics in frequency is promising for developing further such types of magnetic composite.

Magnetic and Magnetocaloric Properties of Nano- and Polycrystalline Manganites La(0.7-x)EuxBa0.3MnO3

Here, we report synthesis and investigations of bulk and nano-sized La_(0.7-x)Eu_xBa_0.3MnO₃ (x ≤ 0.4) compounds. The study presents a comparison between the structural and magnetic properties of the nano- and polycrystalline manganites La_(0.7-x)Eu_xBa_0.3MnO₃, which are potential magnetocaloric materials to be used in domestic magnetic refrigeration close to room temperature. The parent compound, La_0.7Ba_0.3MnO₃, has Curie temperature T_C = 340 K. The magnetocaloric effect is at its maximum around T_C. To reduce this temperature below 300 K, we partially replaced the La ions with Eu ions. A solid-state reaction was used to prepare bulk polycrystalline materials, and a sol-gel method was used for the nanoparticles. X-ray diffraction was used for the structural characterization of the compounds. Transmission electron spectroscopy (TEM) evidenced nanoparticle sizes in the range of 40-80 nm. Iodometry and inductively coupled plasma optical emission spectrometry (ICP-OES) was used to investigate the oxygen content of the studied compounds. Critical exponents were calculated for all samples, with bulk samples being governed by tricritical mean field model and nanocrystalline samples governed by the 3D Heisenberg model. The bulk sample with x = 0.05 shows room temperature phase transition T_C = 297 K, which decreases with increasing x for the other samples. All nano-sized compounds show lower T_C values compared to the same bulk samples. The magnetocaloric effect in bulk samples revealed a greater magnetic entropy change in a relatively narrow temperature range, while nanoparticles show lower values, but in a temperature range several times larger. The relative cooling power for bulk and nano-sized samples exhibit approximately equal values for the same substitution level, and this fact can substantially contribute to applications in magnetic refrigeration near room temperature. By combining the magnetic properties of the nano- and polycrystalline manganites, better magnetocaloric materials can be obtained.

Invar/WC Composite Compacts Obtained by Spark Plasma Sintering from Mechanically Alloyed Powders

The composite materials are used on an increasingly large scale in top fields, such as the automotive, aerospace, and nuclear industries, due to the combination of the specific properties of the composite components. Invar/WC nanocrystalline composite compacts were successfully obtained by spark plasma sintering from mechanical milled composite powder. The influence of the amount of tungsten carbide (WC) on sintering, coefficient of thermal expansion (CTE), and hardness has been investigated. The relative density and hardness of Invar/WC composite compacts increases with increasing the WC content up to 10 vol.%. At higher amount of WC (15% vol.), the relative density and hardness of the Invar/WC composite compacts decreases. The temperature up to which CTE remains at a low value (0.6-1) × 10^-6 °C^-1 is influenced by the WC content and decreases with the WC amount of increase.

Experimental Investigation of the Tribological Behaviors of Carbon Fiber Reinforced Polymer Composites under Boundary Lubrication

Friction and wear experiments were performed on carbon fiber-reinforced polymer (CFRP) composites, and the tribological behavior of these materials under boundary lubrication (based on the 5100 4T 10 W-30 engine oil with TiO₂ Degussa P25 nanoparticles) was investigated. Experiments were carried out in two directions: one at a different normal load from 6 to 16 N and one at a low sliding speed of 110 mm/min under boundary lubrication conditions. The obtained results reveal the stick-slip effect and the static and dynamic coefficient of friction decreased slightly with increasing normal applied load on the carbon fiber reinforced polymer composite pairs. The second direction highlights through experimental tests on the pin on disc tribometer that the friction coefficient increases with the increase in normal load (20–80 N) and sliding velocity (0.4–2.4 m/s). On the other hand, it is found that the friction coefficient is slightly lower than in the stick-slip phase. During the running-in process, the friction coefficient of the CFRP pair increases steadily as the rubbing time increases, and after a certain rubbing period, it remains constant regardless of the material of the counter face. The obtained results show that for the observed interval, the influence of normal load and sliding velocity have relatively small fraction coefficients and low wear depths. A 3D analysis of the profile demonstrated the texture of wear marks and tracks of these engineering composite materials. Furthermore, the height variations of wear marks and the morphologies of the worn surfaces of specimens under boundary lubrication conditions were analyzed.

New Composite Materials Made from Rigid/Flexible Polyurethane Foams with Fir Sawdust: Acoustic and Thermal Behavior

The aim of this work is to obtain new materials with improved sound absorbing and thermal properties, using rigid or flexible polyurethane foam reinforced with recycled fir sawdust from wood processing as well as by optimizing their mixing ratio. In this respect, we prepared and characterized samples by mixing rigid polyurethane foam (RPUF)/flexible polyurethane foam (FPUF) with 0, 35, 40, 45, and 50 wt% fir sawdust (FS) with grains size larger than 2 mm. The samples were evaluated by cell morphology analysis, sound absorption, and thermal insulation performance. The obtained composite materials containing 50% sawdust have superior acoustic properties compared to those with 100% FPUF in the range of 420-1250 Hz. The addition of 35% and 50% FS in the FPUF matrix led to improved thermal insulation properties and decreased thermal insulation properties in the case of RPUF. The results show that the use of FS-based composites with the FPUF/RPUF matrix for sound absorption and thermal insulation applications is a desirable choice and could be applied as an alternative to conventional synthetic fiber-based materials and as a recycling method of waste wood.

3D Printed Microfluidic Bioreactors Used for the Preferential Growth of Bacterial Biofilms through Dielectrophoresis

A realistic modelling of the way biofilms form and evolve in time requests a dynamic approach. In this study, the proposed route uses continuous-flow bioreactors under controlled flow rates and temperature in the culture medium containing bacteria or fungi. 3D printed, Polylactic acid (PLA), flow-based bioreactors with integrated copper electrodes were used to investigate the effect of dielectrophoresis on the formation and growth of Staphylococcus aureus ATCC 25923, Enterococcus faecalis ATCC 29212, Pseudomonas aeruginosa ATCC 27853, and Klebsiella pneumoniae ATCC 13883 biofilms. Bacterial suspensions of 1McF turbidity have been prepared and circulated through the bioreactors. At the same time, a 30 V potential difference was applied on the system. The effect of the non-uniform electric field induced upon the bacterial cells was determined using quantitative methods, such as an adjusted microtiter plate technique, as well as spectral domain optical coherence tomography (SD-OCT) images. The morphology and the surface quality of the biofilms were investigated using Scanning Electron Microscopy (SEM) images. The results show that the different bacterial cells present a positive dielectrophoretic behaviour, with the preferential formation of biofilms in the high field gradient region.

Analysis of Sheep Wool-Based Composites for Building Insulation

The aim of this paper is to propose ecological thermal insulation materials that meet the goals of sustainability but also fulfill the imposed thermal performance requirements. This paper studies new composite materials based on sheep wool from the perspective of thermal conductivity. The composites were prepared using two types of binder: acrylic-polyurethane resin and natural rubber latex, which were applied to the wool fibres through different methods and percentages. Based on the obtained results of thermal conductivity, two types of samples were selected for further analysis, which aimed to determine the microstructure, chemical composition, water absorption, attack of microorganisms, water vapour permeability, hygrothermal adsorption characteristics and sound absorption of the samples. In order to analyse the variation of thermal conductivity, the following parameters were taken into account: thickness, density, type of binder and percentage of binder. Following the obtained results, it was observed that the value of the thermal conductivity of the samples varies between 0.0324 and 0.0436 W/mK. It was found that all the samples prepared and analysed in this study fulfil the national criteria for the thermal performance of thermal insulation material. After conducting the in-depth analysis of the two selected sample types, it was concluded that both materials have good sound absorption characteristics over the considered frequency range. In addition, as it was expected from the natural fibres, the samples had low resistance against the attack of microorganisms and water-related tests.

The crystal structure of Rb2Ti2O5

Recent results have demonstrated an exceptionally high permittivity in the range 200–330 K in crystalline titanium oxide Rb2Ti2O5. In this article, the possibility of a structural transition giving rise to ferroelectricity is carefully inspected. In particular, X-ray diffraction, high-resolution transmission electron microscopy and Raman spectroscopy are performed. The crystal structure is shown to remain invariant and centrosymmetric at all temperatures between 90 K and 450 K. The stability of the C2/m structure is confirmed by density functional theory calculations. These important findings allow the existence of a conventional ferroelectric phase transition to be ruled out as a possible mechanism for the colossal permittivity and polarization observed in this material.

Abdominal Wall Reconstruction after Flap Surgery and the Effect on the Immune System

BACKGROUND

The aim of our study was to investigate the impact of abdominal wall reconstruction surgery on tissue anatomy and to explore how flap surgery influences the patient's immune status.

METHODS

Experimental abdominal wall defects were created in 8 Sus scrofa (swine) animal models. The animals were divided into two groups: 4 swine were euthanized one month after surgery for the biopsies retrieval purpose and the other 4 swine were kept alive and the collection of blood samples has been done 6 months after surgery. In order to evaluate the relative gene expression in operated-on animal cohorts we compared them with samples from 4 healthy swine used as controls.

RESULTS

The inflammatory process was present in all types of repairs. Collagen I deposition was higher in the flap repairs. The expression level for the genes related to immune response after 6 months from surgery was relatively similar to the control group except minor alteration registered in the case of two swine models.

CONCLUSION

Our findings indicate a less pronounced proinflammatory response to surgical trauma in animal models after flap surgery. The postoperative levels of the inflammatory cytokines did not show significant differences after abdominal wall reconstruction using flap surgery.

Criteria to define a more relevant reference sample of titanium dioxide in the context of food: a multiscale approach

Titanium dioxide (TiO₂) is a transition metal oxide widely used as a white pigment in various applications, including food. Due to the classification of TiO₂ nanoparticles by the International Agency for Research on Cancer as potentially harmful for humans by inhalation, the presence of nanoparticles in food products needed to be confirmed by a set of independent studies. Seven samples of food-grade TiO₂ (E171) were extensively characterised for their size distribution, crystallinity and surface properties by the currently recommended methods. All investigated E171 samples contained a fraction of nanoparticles, however, below the threshold defining the labelling of nanomaterial. On the basis of these results and a statistical analysis, E171 food-grade TiO₂ totally differs from the reference material P25, confirming the few published data on this kind of particle. Therefore, the reference material P25 does not appear to be the most suitable model to study the fate of food-grade TiO₂ in the gastrointestinal tract. The criteria currently to obtain a representative food-grade sample of TiO₂ are the following: (1) crystalline-phase anatase, (2) a powder with an isoelectric point very close to 4.1, (3) a fraction of nanoparticles comprised between 15% and 45%, and (4) a low specific surface area around 10 m² g^-1.

Immunotherapy and gene therapy in prostate cancer treatment

There are few methods bringing several relatively recent advances in therapy of certain types of prostate cancer. Belonging to personalized therapies, they use cells (normal or pathologic) from the patient, modify and reintroduce them in the patient's body, leading to an increased efficiency against the neoplastic tissue, proving to increase the patient's lifespan and/ or tumor progression.

Prostate cancer between prognosis and adequate/proper therapy

Knowing the indolent, non-invasive nature of most types of prostate cancer, as well as the simple fact that the disease seems more likely to be associated with age rather than with other factors (50% of men at the age of 50 and 80% at the age of 80 have it [1], with or without presenting any symptom), the big challenge of this clinical entity was to determine severity indicators (so far insufficient) to guide the physician towards an adequate attitude in the clinical setting. The risk of over-diagnosing and over-treating many prostate cancer cases (indicated by all the major European and American studies) is real and poses many question marks. The present paper was meant to deliver new research data and to reset the clinical approach in prostate cancer cases.

Ultrasonography in the diagnosis and management of non inflammatory conditions of the hand and wrist

High resolution ultrasonography has already become an important tool in the diagnosis and management of inflammatory arthritis of the hand and wrist but lately it has been proven to be the method of choice in the evaluation of traumatic lesions of tendons, annular pulleys, nerves, and ligaments and at the same time in detecting foreign bodies. The objective of this paper is to review and describe the current knowledge on these US findings and to highlight the ultrasonography role in the evaluation of non-inflammatory conditions of the hand and wrist.

The etiopathogenesis of uterine fibromatosis

Uterine fibroids or uterine leiomyomas are the most common benign tumors of the uterus among women of fertile age, while the etiology is still incompletely elucidated. The occurrence and development of the fibromatosis may be related to certain risk factors and genic mechanisms, although the exact causes are not yet fully known. The development of uterine fibroids is correlated not only with the metabolism and with the level of female sexual hormones, estrogen, and progesterone, but also with the number of these hormone receptors expressed on the surface of the myometrium. Proliferative effects of estrogen and progesterone may be exercised through proinflammatory factors (TNF alpha), growth factors (IGF1, IGF2, TGFbeta3 and betaFGF) or inhibitors of apoptosis (p53 suppression). A number of predisposing factors such as ethnicity - black skin, early menarche, nulliparity, caffeine and alcohol, chronic inflammation, obesity, were also identified. Approximately 40% of the uterine fibroids are caused by the same cytogenetic alterations found in the other tumor types such as kidney, lung, or leiomyosarcoma. As part of a system dysfunction, uterine fibromatosis was connected to other disorders such as AHT (arterial hypertension), endometrium adenocarcinoma, adenomyosis, endometriosis, diabetes mellitus, breast tumors, seemingly with a common causality. The action and effect of some hormonal imbalances over the various organs depend on the histological and local expression particularities of the various receptors, being the cause for many disorders, among which the uterine fibromatosis, coexisting or accompanying the later. This article examines and summarizes the latest data refreshed literature etiopathogenesis offering indicators of uterine fibroids.

Focal adenomyosis (intramural endometriotic cyst) in a very young patient - differential diagnosis with uterine fibromatosis

Introduction. Adenomyosis is a widespread disease usually affecting the late reproductive years of the women's life, which has a great impact on their fertility. The most common form is diffuse adenomyosis, while focal adenomyosis, a cystic variant, is very rare, particularly in patients younger than 30 years old. Materials and methods. We reported a rare case of a 20-year-old Caucasian woman with cystic adenomyosis who was admitted in our service with severe chronic pelvic pain, dysmenorrhea, and menorrhagia, who had received conservative surgical treatment to preserve fertility and improve her obstetrical prognosis. Results and Discussions. Although the necrobiosis of a uterine fibroid was suspected preoperatively, the extemporaneous histopathological exam revealed adenomyosis associated with fibroleiomyoma with hyaline dystrophy and multiple foci of endometriosis of cystic formation in the wall of a young woman without any risk factors. Conclusion. Although a rare lesion in young patients, cystic adenomyosis should be considered when chronic pelvic pain is exacerbated during menstruation and is associated with a uterine tumor. In young patients, the differential diagnosis should be made with uterine malformations (hematometra), necrobiosis of uterine fibroids, pelvic endometriosis. The surgical treatment should be conservative with the excision of the lesion, always taking into account fertility preservation in young patients.

Measurement of Quality of Life after Total Parathyroidectomy in Patients with Secondary Hyperparathyroidism and End Stage Renal Disease

BACKGROUND

Surgery is the definitive treatment of secondary hyperparathyroidism (2HPT) and end stage renal disease patients. The aim of this study to assess the impact of surgery on the evolution of quality of life (QoL) in patients with 2HPT, and to identify the variables that influence this evolution.

METHODS

A series of 85 consecutive unselected patients underwent total parathyroidectomy for 2HPT in our clinic. QoL was measured using the Short-Form Health Survey(SF-36) and alleviation of symptoms was documented using an outcome tool (PAS score), based on visual analog scales, preoperatively, postoperatively and at 6 months.

RESULTS

Preoperatively, patients had lower SF-36 scores than the general population in all 8 individual and 2 component summary scales, with significant decrease in the physical health scales(p 0.0001). Patients improved in all ten scales at 6 months follow-up, most significant being: Body Pain (45.02‚+-5.52 vs 33.12‚+-8.82, p 0.0001), Role-physical (41.00‚+-7.43 vs 33.46‚+-8.54, p 0.0001), Physical functioning (40.06 ‚+-7.77 vs 33.36 ‚+-10.84, p 0.0001). PAS Scores decreased from preoperatory levels of 569.99 ‚+- 136.45 to 372.20 ‚+- 104.62 at 7 days after surgery and furthermore at 292.64 ‚+- 85.16 at 6 months follow-up (p 0.0001).

CONCLUSIONS

We found no correlation between preoparatory PTH or Calcium levels and clinical symptoms. Parathyroidectomy clearly alleviates symptomatology and improves QoL in 2HPT patients, with durable effect at 6 months.

Curcumin delivered through bovine serum albumin/polysaccharides multilayered microcapsules

The aim of the paper is to obtain and characterize k-carrageenan–chitosan dual hydrogel multilayers shell BSA gel microcapsules, as a carrier for curcumin, and as a possible antitumoral agent in biological studies. We used the CaCO3 template to synthesize non-toxic CaCO3/BSA particles as microtemplates by coprecipitating a CaCl2 solution that contains dissolved BSA, with an equimolar Na2CO3 solution. The microcapsules shell is assembled through a layer-by-layer deposition technique of calcium cross-linked k-carrageenan hydrogel alternating with polyelectrolite complex hydrogel formed via electrostatic interactions between k-carrageenan and chitosan. After the removal of CaCO3 through Ca2+ complexation with EDTA, and by a slightly treatment with HCl diluted solution, the BSA core is turned into a BSA gel through a thermal treatment. The BSA gel microcapsules were then loaded with curcumin, through a diffusion process from curcumin ethanolic solution. All the synthesized particles and microcapsules were stucturally characterized by: Fourier Transform Infrared Spectroscopy, UV–Vis Spectrometry, X-ray diffraction, thermal analysis, fluorescence spectroscopy, fluorescence optical microscopy, confocal laser scanning microscopy and scanning electron microscopy. The behavior of curcumin loaded microcapsules in media of different pH (SGF, SIF and PBS) was studied in order to reveal the kinetics and the release profile of curcumin. The in vitro evaluation of the antitumoral activity of encapsulated curcumin microcapsules on HeLa cell line and the primary culture of mesenchymal stem cells is the main reason of the microcapsules synthesis as BSA-based vehicle meant to enhance the biodisponibility of curcumin, whose anti-tumor, anti-oxidant and anti-inflammatory properties are well known.

Technical Factors Involved in Parathyroid Surgery

We aimed to investigate the frequency of ectopic and supernumerary parathyroid glands in our series of renal hyperparathyroidism. From October 2011 to November 2014, 202 patients with chronic renal failure and advanced SHPT nonresponsive to medical therapy were hospitalized in the General Surgery Department of the Carol Davila Nephrology Hospital. These patients underwent a number of 188 (93%) total parathyroidectomies and a number of 14 patients (7%) subtotal parathyroidectomies. Of these 202 patients, reoperation was carried out for 14 patients (7%) in which we identified ectopic and supernumerary parathyroid glands. Operative details and pathology results were prospectively collected and reviewed after we obtained informed consent for data and pictures use. In 188 patients (93% cases), four or more parathyroid glands were removed at the first operation. In 14 cases (7%) high PTH level persisted after the initial operation. In 22 of them (11%), supernumerary glands were found at the first operation and in 6 of them (3%) at the second operation. We conclude that extensive cervical exploration in addition with preoperative imaging tests, parathyroid ultrasound; scintigraphy with Tc will reduce secondary hyperparathyroidism surgery.

Surgical Attitude in Patients with Secondary Hyperparathyroidism Undergoing Dialysis

BACKGROUND

Secondary hyperparathyroidism (SHPT), develops, more or less in all the patients with chronic kidney disease. The pathology is even more severe as it intervenes in a suffering patient in whom the chronic kidney disease frequently associates severe comorbidities. General mortality is higher than in general population. The failure of the medical therapy is an indication for parathyroidectomy.

METHODS

The study analyzed 200 patients with SHPT and chronic kidney disease, admitted in the clinic from October 2011 until January 2015.In this period, 179 (89.5 %) total-parathyroidectomies have been performed a long with 14 (7%) subtotal parathyroidectomies. Also 7 (3.5%) surgical interventions were incomplete.

RESULTS

Overall mortality was 1% (2 patients) and postoperative specific morbidity 3.5% -4 local hemorrhagic complications and 3 cases of dysphonia have been encountered (12% if we include the reinterventions for recurrent hyperparathyroidism - 17 patients).

CONCLUSIONS

Total parathyroidectomy is encumbered by a reduced number of postoperative complications and the risk of recurrent disease in almost nonexistent. The disadvantages of this surgical approach are the tendency of immediate postoperative hypocalcemia and long therm substitution with calcium and vitamine D.

The Role of Collagen Metabolism in the Formation and Relapse of Incisional Hernia

Despite the continuous development of synthetic prosthetic meshes and their wide use, recurrent incisional hernias still appear in 5 to 20% of cases, with a linear incidence curve over the years, suggesting a multifactorial process rather than a simple failing technical repair as the underlying cause. Recent molecular biological research provide increasing evidence of connective tissue alterations such as a defective wound healing with impaired scarring process in patients with incisional hernia. Although there are some promising results, at present, in-depth understanding of the pathophysiological mechanisms and of the role that collagens play in the development and recurrence of incisional hernia is rather scarce. The aim of this systematic review is to summarize and evaluate the biochemical mechanisms involved in incisional hernia formation and recurrence, with a primary focus on collagen I to III ratio. Also, the consequences for surgical practice are discussed.

Spontaneous rupture of a splenic hydatid cyst with anaphylaxis in a patient with multi-organ hydatid disease

Hidatid cysts of the spleen are a rare occurrence, the spleen being the third most common organ for the development of Echinococcus Granulosus. Splenic hydatid cysts are commonly part of multi-organ hydatid disease. Diagnosis is often established when investigating a splenomegaly or by chance during an unrelated consult. It can also be diagnosed after rupture, be it following trauma (the most common occurrence)or spontaneous. Splenic hydatid cyst rupture requires immediate action and is a life-threatening condition. It results, most often, in splenectomy. We present the case of a patient with multi-organ hydatid disease that presented with a ruptured splenic cyst and developed anaphylaxis. The case was resolved by splenectomy and recovered well.

Translating clinical research of Molecular Biology into a personalized, multidisciplinary approach of colorectal cancer patients

Although multimodal treatment has brought important benefit, there is still great heterogeneity regarding the indication and response to chemotherapy in Stage II and III, and individual variations related to both overall survival and toxicity of new therapies in metastatic disease or tumor relapse. Recent research in molecular biology led to the development of a large scale of genetic biomarkers, but their clinical use is not concordant with the high expectations. The Aim of this review is to identify and discuss the molecular markers with proven clinical applicability as prognostic and/or predictive factors in CRC and also to establish a feasible algorithm of molecular testing, as routine practice, in the personalized, multidisciplinary approach of colorectal cancer patients in our country. Despite the revolution that occurred in the field of molecular marker research, only Serum CEA, Immunohistochemical analysis of mismatch repair proteins and PCR testing for KRAS and BRAF mutations have confirmed their clinical utility in the management of colorectal cancer. Their implementation in the current practice should partially resolve some of the controversies related to this heterogenic pathology, in matters of prognosis in different TNM stages, stage II patient risk stratification, diagnosis of hereditary CRC and likelihood of benefit from anti EGFR therapy in metastatic disease. The proposed algorithms of molecular testing are very useful but still imperfect and require further validation and constant optimization.

Stump appendicitis - an overlooked clinical entity

Stump appendicitis is a rare disease, often overlooked. Thepossibility of stump appendicitis is not clear to all clinicians.It can represent a diagnostic dilemma if the treating physicianis not aware of this uncommon disease. Presenting symptomsare indistinguishable from those of primary appendicitis. Wepresent two cases of stump appendicitis operated in ourdepartment and their treatment. A heightened awareness ofthe possibility of this disease can lead to good initial surgical technique and prevention, and to early diagnosis in the eventof stump appendicitis.

Predictive value of POSSUM score in surgery of acute abdomen in cirrhotic patients

INTRODUCTION

As liver cirrhosis has an increasing incidence in the general population and the life expectancy for these patients has increased, surgery procedures practiced for acute abdomen in such category of patients are more frequent.

AIM

To evaluate the predictive value of POSSUM score in cirrhotic patients undergoing abdominal surgery in emergency cases.

MATERIAL AND METHOD

A prospective study based on 115 consecutive patients with liver cirrhosis hospitalized and operated in the first 24 hours from admission for acute abdomen. The patients' stratification was done by using Child Pugh score for liver cirrhosis. POSSUM score was calculated for each patient and postoperative outcomes were compared with prediction based on this score. Statistical data analysis was made by using the chi-square test and a p value of less than 0,05 was considered to be statistically significant.

RESULTS

There were 33 patients in stage Child A of cirrhosis, 54 in stage Child B and 28 in stage Child C. For Child A group, the POSSUM score had a satisfactory prediction in terms of morbidity and mortality. In advanced stages of liver cirrhosis, Child B and C, mortality had high rate and the observed outcomes were outside the area of POSSUM score prediction.

CONCLUSIONS

POSSUM score offers a satisfactory prediction for morbidity and mortality in emergency abdominal surgery for patients in compensated stages of liver cirrhosis. In advanced stages of cirrhosis high levels of mortality cannot be predicted by using POSSUM score.

Intraoperative cholangiography still a current investigation

Laparoscopic cholecystectomy is the standard treatment for patients requiring gallbladder removal. Although the advantages of the laparoscopic technique are widely accepted, the introduction of this technique has doubled the rate of iatrogenic lesions of extrahepatic bile ducts. Research methods for biliary tree also evolved, but intraoperative cholangiography, the traditional exploring method used for the biliary tree in classic cholecystectomy remains a valuable investigation in the laparoscopic technique. We performed a retrospective study on a group of patients who underwent cholecystectomy (laparoscopic or classic). Of these, intraoperative cholangiography was performed on a total of 108 patients. Patients who underwent cholangiography motivated by preoperative investigations were excluded from the group and the study operates on patients in whom the decision to perform cholangiography was taken during surgery (45 cases). We have analyzed the criteria that led to the motivation investigation (dilated cystic duct, suspected biliary duct stones, suspicion of iatrogenic biliary injury) results and subsequent therapeutic conduct. The results showed that in 90% of the patients, the suspected diagnosis was confirmed by cholangiography (10 cases with normal cholangiography aspect, oddita 9 cases, 11 cases with bile duct stones, 2 cases with biliary tumor and 13 cases of iatrogenic biliary injury). In conclusion, the decision to perform intraoperative cholangiography proved salutary, the suspected diagnosis was confirmed and the course of treatment was adjusted accordingly.

Colic anastomotic leakage risk factors

BACKGROUND

Anastomotic leakage is a dreaded complication of colorectal surgery, as it greatly increases the morbidity, mortality and has been associated with augmented local recurrence and diminished survival. The frequency of this complication is high in emergency colorectal surgery, especially for bowel occlusion, (13% for emergency vs. 4% in elective), due to visceral distension and, therefore, an incongruence in the size of each of the stumps, combined with the lack of mechanical preparation and risk of fecal contamination during operation.

METHODS

We studied the incidence of anastomotic fistula in the surgery clinic of the "Sf. Pantelimon" Emergency Hospital, between 2006 and 2010, on a lot of 251 patients who underwent different types of colic resection. Apart from the anatomic location of the disease, and the level of anastomosis, we included in our database the following criteria: the patient's age and gender, type of colic pathology, surgical technique, emergency or elective surgery, comorbidities.

RESULTS

An ileocolic anastomosis was performed for 84 patients (33,46 %), for 114 patients (45,41%) a colo-colic anastomosis was carried out, 2 patients (0,79%) had ileorectal anastomosis and 51 patients (20,31%) underwent a colorectal anastomosis. From the comparative analysis of risk factors (the emergency interventions, the anastomosis location, the age and gender of the patient), a significantly increased value of the relative risk of anastomotic fistula was registered for the cases with emergency intervention (x 6,61) and for the colorectal anastomosis following the left hemi colectomies (x 2,23).

DISCUSSIONS

In our study, among the clinical and biological factors analyzed, emergency intervention was the most significant factor associated with anastomotic leakage. Surgery performed in emergency settings, on debilitated patients without adequate preoperative preparation, has an increased risk for anastomotic dehiscence.

Microsatellite instability in the management of stage II colorectal patients

BACKGROUND

Up-to-date it is unclear whether stage II colorectal cancer patients should receive adjuvant chemotherapy.The presence of high risk features (T4, CEA 5 ng dl, less than 12 lymph nodes examined) is an indication for Oxaliplatin based treatment. In their absence, there is no consensus, 5 Fluorouracil regimens, or observation only being equally recommended by oncologists. Microsatellite instability is associated with good prognosis in stage II colorectal cancer and also with poor response to 5 Fluorouracil and should be used as a predictive marker.

METHODS

We performed a prospective descriptive study on 115 consecutive patients who received surgical resection for colorectal cancer in our clinic during 2011 and 2012 using a risk stratification algorithm based on TNM staging, clinico pathologic and molecular markers.

RESULTS

From the 44 stage II colorectal cancer patients, 10 cases were classified as high risk, in 26 cases we performed Immunohistochemical analysis that identified 8 patients with low risk microsatellite instability phenotype, with no indication for adjuvant chemotherapy; 26 intermediate risk patients received 5-FluoroUracil regimens.

CONCLUSION

We believe that microsatellite instability testing provides a useful tool in the goal of better characterizing patients with stage II colorectal cancer in matters of risk of recurrence and likelihood of benefit from chemotherapy.

The implications and consequences of maternal obesity on fetal intrauterine growth restriction

CONTEXT

The prevalence of maternal obesity has been increasing dramatically in the recent years (body mass index ≥ 30 kg/m2). Maternal obesity is associated with an unequivocal increase in maternal and fetal complications of pregnancy and more than that, these complications also extend beyond fetal life in childhood and adulthood. Objective. The aim of this study was to evaluate maternal and neonatal complications at birth associated with maternal obesity.

MATERIALS AND METHODS

The study included all women who gave birth between January 1, 2012 and December 31, 2012 at Bucharest University Emergency Hospital. Collected data included information about maternal health (the degree of obesity, associated complications of birth, anemia, and type of birth) and neonatal status (birth weight, gestational age, associated diseases and Apgar score).

RESULTS

A higher incidence of IUGR, as well as an increased frequency of infants who needed intensive care after birth, a higher rate of cesarean surgery and a higher frequency of thromboembolic complications were observed in patients with associated obesity.

CONCLUSIONS

Complications grow both in number and severity with increasing obesity. Diagnosis of the fetuses with IUGR is important for the monitoring and management of the pregnancy associated with obesity and it involves a close collaboration between obstetrician, family physician and neonatologist.

Prognosis elements in surgical treatment of complicated umbilical hernia in patients with liver cirrhosis

INTRODUCTION

The surgical treatment of umbilical hernia in cirrhosis patients raises special management challenges. The attitude upon the repair of these hernias varies from expectancy or elective treatment in early stages of the disease to the surgical treatment only if complications occur.

MATERIAL AND METHOD

We have assessed 22 consecutive cases of cirrhosis patients treated for complicated umbilical hernia in the Surgical Department of "Sf. Pantelimon" Emergency Hospital in Bucharest between January 2008 and December 2012. The patients' stratification was done in stages of liver disease based upon Child-Pugh classification. Complications that required emergency repair were the following: strangulation, incarceration and hernia rupture. The postoperative complications were ordered in five grades of severity based upon Clavien classification.

RESULTS

The severity of the complications was higher in advanced stages of liver cirrhosis, Child B and C. There were 5 deaths representing 22,7%, four of them in patients with Child C disease stage.

CONCLUSION

The incidence of morbidity and mortality after umbilical hernia repair in emergencies increases in advanced stages of liver cirrhosis. It is advisable to prevent complications occurrence and perform surgical repair of umbilical hernia in elective condition.

Necrotizing enterocolitis, a rare but severe condition with insidious postoperative complications

Necrotizing enterocolitis (NEC) is one of the most frequent causes of gastrointestinal perforation in premature neonates, only few case series and reports being described in adult patients. Early in the course of the disease, superficial mucosal ulceration, sub mucosal edema and hemorrhage occur. Further progression leads to transmural necrosis leading sometimes to bowel perforation. Six cases encountered in our clinic in recent years led us to resume discussions on necrotizing enteritis, not because it is a rare disease, but due to the severe postoperative complications.

MATERIAL AND METHODS

Our lot consisted of four stage 1 patients and two with Bell stage III NEC and severe intestinal injury, necrosis, and perforation. All of the patients were diagnosed preoperatory with other surgical conditions, like appendicitis with peritonitis, perforated duodenal ulcer or acute cholecystitis.

RESULTS

We present to review two cases. For patients undergoing laparotomy, resection of the involved intestine mandates either enterostomy formation or primary anastomosis. An intermediate option is laparotomy with intestinal resection and delayed anastomosis 48 to 72 hours later. Because of the small number of patients in our lot, we cannot advise a certain surgical treatment, but a strategy involving bienterostomyper primam should be further analyzed. The choice of operative intervention reflects multiple variables, including age, physiologic status, institutional resources and surgeon preference based on experience. Primary peritoneal drainage for perforated NEC may help to resuscitate and treat a critically ill patient initially, and in some instances, may be definitive operative intervention.

CONCLUSIONS

Relatively rare disease, of unknown etiology and elusive pathogenesis, NEC has initial non-specific symptoms and clinical features that mimic more common surgical diseases. There is considerable controversy regarding which procedure is preferable. Currently, in the absence of rigorous evidence supporting the superiority of one approach over the other, surgical intervention depends mostly on the treating institution or the individual surgeon.

Zenker's diverticulum, a rare cause of upper gastrointestinal bleeding

The most common complication of Zenker's diverticulum is aspiration pneumonia, compression of the trachea and esophageal obstruction with large diverticulum, and increased risk of development of carcinoma. Thus bleeding occurs rarely, can be massive and life threatening, with ulceration being the most common cause.

MATERIAL AND METHODS

We describe a patient with sever upper gastrointestinal bleeding as a result of a Zenker's diverticulum. A 75 year-old woman was referred to the emergency room and hospitalized for hematemesis, melena, asthenia and total dysphagia. In this particular case we preferred open technique because of the diverticulum dimensions and bleeding episode. Left cervicotomy was practiced on the anterior edge of the sternocleidomastoid muscle, being known that Zenker diverticulum extend into the left neck 90% of the time, fact also confirmed by radiology in this case.

RESULTS

Postoperatively, the patient showed a complication free recovery. Five days after treatment the patient resumed nourishment. Several days later our patient was able to return home. Follow-up at 12 months after the operation showed complete recovery. Ulcer of the basis of Zenker's diverticulum is a rare entity and, only a few cases were reported in the literature to date. Omitting thecricomyotomy predisposes to fistula or diverticulum recurrence due to the persistence of a high pharyngeal intraluminal pressure that acts on the posterior wall just proximal to the upper esophageal sphincter.

CONCLUSIONS

Zenker's diverticulum is an unusual site of origin for clinically significant upper gastrointestinal hemorrhage and differential diagnosis must include other more frequent causes of upper gastrointestinal bleeding. In our opinion, classicalsurgical therapy is indicated when distal esophageal imaging cannot be obtained during endoscopic examination, there is a large diverticulum or in an emergency setting when fast control over the bleeding source is required.

Umbilical hernia alloplastic dual-mesh treatment in cirrhotic patients

RATIONALE

Abdominal wall hernias represent a pathology with an impressive prevalence among the population of patients with cirrhosis complicated by ascites. The aggressive surgical approach of umbilical hernia for patients with cirrhotic background remains a controversial problem, accompanied by anesthetic and surgical risk. Its indication remains fully justified in case of severe symptoms or life threatening complications: strangulation, incarceration, evisceration.

OBJECTIVE

This article evaluates results obtained by using dual-mesh alloplastic materials for surgical treatment of umbilical hernias affecting cirrhotic patients with incipient liver injury.

METHODS AND RESULTS

Our lot consists of twelve patients with ages between 45 and 65 years, diagnosed with hepatic cirrhosis, without other associated comorbidities. All patients were admitted for strangulated umbilical hernia. Among the analyzed lot, no decease was encountered, the morbidity being limited to two cases of parietal suppuration, solved conservatively, without the mesh removal. There were no ascitic fistulas. No recurrences were registered for a 12 months tracking period.

DISCUSSION

The presence of cirrhosis implies a high anesthetic and surgical risk, the intervention being grafted by a substantial increase of mortality and morbidity in an emergency setting. The development of new alloplastic materials, together with the modern anesthetic techniques, allows superior results for patients with incipient hepatic injury.

Molecular factors of failure in incisional hernia surgery

Incisional hernias occur as frequent as they did 20 years ago even if we use modern technologies in terms of suture. Sutures techniques, either primary repair or applied after failure of primary repair are characterized by high rates of recurrence. Using the hernia mesh has become mandatory in repairing of all types of hernias - inguinal, ventral or incisional. Implantation of the mesh is a relatively well-coded surgical procedure. But surgery is only the first step in the process of healing. Implantation starts a strong response with haematological mechanisms: protein absorption, complement activation, coagulation, platelet activation, neutrophil activation and tissue mechanisms: proliferation, adhesion, fibrosis. Recurrence rates are consistently lower when replacement meshes are used and a variety of meshes have been developed for this purpose. How the mesh is embedded by the human body and how the biomechanical limits of the abdominal wall are restored is still a subject of debate for surgeons. Histopathological studies and progress in design and materials are the only keys to solve this problem. Also pathological studies should determine the right material for personalized repair according to each patient's biology. This paper attempts to analyze the molecular failure factors in incisional hernia surgery, different from errors in surgery procedures. Complications can be avoided or reduced by an appropriate selection of the type of place in a particular case, and by performing a meticulous technique. Incisional hernias are considered at this moment a biological progressive phenomenon, and not only a strictly technical one, a "simple hole in the abdominal wall" that has to be firmly sutured.

Rives technique, a gold standard for incisional hernias -- our experience

Incisional hernias are a real problem in abdominal surgery and occur in up to 18% of patients undergoing surgery. Simple sutures or so-called anatomical processes lead to recurrence in up to 50% of cases. Performance of an alloplastic procedure decreases relapse rate to 10%, down from 12%. Popularized in Europe by Rives and Stoppa, the sublay mesh repair technique has proven very effective, with low recurrence rates (0% -23%) and minimal complications. In our clinic we have been using this technique for about 10 years, adding some changes that we consider beneficial to the further evolution of the patient and especially to obtaining a strong abdominal wall, equally functional in terms of bio-mechanics. During the study period, we recorded a total of 45 patients with abdominal incisional hernias operated by this technique. All patients were operated on by the same surgical team. No patients required surgical reintervention. Our results show that the Rives-Stoppa technique is an effective method for repairing incisional hernias. Complications and recurrence rates are comparable with the results of other techniques.