Electrical and Photodetector Characteristics of Schottky Structures Interlaid with P(EHA) and P(EHA-co-AA) Functional Polymers by the iCVD Method.

In this study, poly(2-ethylhexyl acrylate) (PEHA) homopolymer and its copolymer combined with acrylic acid P(EHA-co-AA) were employed as interfaces in two separate Schottky structures. First, both interfaces were grown by initiated chemical vapor deposition (iCVD), which provides much better deposition control and homogeneous coating compared to solution-phase methods. In addition to this advantageous method, the effects of two different polymers, one of which is better able to adhere to the crystal surface on which it is formed than the other, on the optoelectronic properties have been studied. Then, their current-voltage (I-V) and capacitance/conductance-voltage (C/(G/ω)-V) characteristics were investigated both in the dark and under illumination. The basic electrical parameters and the illumination-induced profile of the surface state (Nss) were probed by I-V and C-V measurements for two samples. A decrease in the barrier height (BH) and, consequently, a significant increase in the photocurrent were observed under illumination. Striking changes in series resistance (Rs) values are also highlighted. The photocapacitance and conductance characteristics indicated that the structures could be considered not only as photodiodes but also as photocapacitors. Moreover, the voltage-dependent changes of some photodetector parameters, such as responsivity (R), sensitivity (S), and specific detectivity (D*), along with the transient photocurrent characteristics, are discussed for both structures. Therefore, we can say that the strong changes in these parameters, which figure the merit of photodiode and photodetector applications, depending on the voltage and under illumination, prove that it is a study carried out in accordance with the purpose and so they can be used in electronic and optoelectronic applications.

A Comparative Study on UHPLC-HRMS Profiles and Biological Activities of Inula sarana Different Extracts and Its Beta-Cyclodextrin Complex: Effective Insights for Novel Applications.

Within this particular framework, the extracts obtained from Inula sarana using a variety of solvents, included n-hexane, ethyl acetate, dichloromethane (DCM), 70% ethanol, ethanol, and water. The extracts obtained from n-hexane, ethyl acetate, and DCM were then subjected to a specific method for their incorporation into ß-cyclodextrin (ß-CD). The establishment of complex formation was validated through the utilization of scanning electron microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The identification of phytochemical components was executed using UHPLC-HRMS. Furthermore, the total phenolic and flavonoid content was evaluated using the Folin-Ciocalteu assay and the AlCl3 method. Subsequently, the determination of antioxidant capacity was conducted utilizing DPPH, ABTS, CUPRAC, Frap, PBD, and MCA assays. The enzyme inhibitory activities of the samples (extracts and ß-CD complexes) were also examined by AChE, BChE, tyrosinase, α-glucosidase, and α-amylase. The findings indicated that water and 70% ethanol extracts contained the highest phenolic content. One hundred and fourteen bioactive compounds were identified by UHPLC-HRMS analysis. This study unveiled a substantial array of flavonoids, phenolic acid-hexosides and caffeoylhexaric acids within I. sarana, marking their initial identification in this context. Among the various extracts tested, the 70% ethanol extract stood out due to its high flavonoid content (jaceosidin, cirsiliol, and eupatilin) and hydroxybenzoic and hydroxycinnamic acid hexosides. This extract also displayed notably enhanced antioxidant activity, with ABTS, CUPRAC, and FRAP test values of 106.50 mg TE/g dry extract, 224.31 mg TE/g dry extract, and 110.40 mg TE/g, respectively. However, the antioxidant values of the complex extracts with ß-CD were generally lower than those of the pure extracts, an observation warranting significant consideration. In terms of enzyme inhibition activity, the ethanol and 70% ethanol extracts exhibited higher inhibitory effects on AChE, tyrosinase, and α-glucosidase. Conversely, n-hexane displayed stronger inhibitory activity against BChE. The ethyl acetate extract demonstrated elevated amylase inhibitory activity. However, the antioxidant values of the complex extracts with ß-CD were generally lower than those of the pure extracts, a noteworthy observation, while water and extracts from the I. sarana complex with ß-CD exhibited minimal or negatable inhibitory activity against specific enzymes.

Responses of individual and combined polystyrene and polymethyl methacrylate nanoplastics on hormonal content, fluorescence/photochemistry of chlorophylls and ROS scavenging capacity in Lemna minor under arsenic-induced oxidative stress.

Nanoplastics alter the adverse impacts of hazardous contaminants such as heavy metals by changing their adsorption and accumulation. Few findings are available on the interaction between nanoplastic and heavy metals in plants. However, there is no report on the mechanisms for removing metal stress-mediated oxidative damage by the combination treatments of nanoplastics. To address this lack of information, polystyrene nanoplastic (PS, 100 mg L-1) and polymethyl methacrylate (PMMA, 100 mg L-1) were hydroponically applied to Lemna minor exposed to arsenate (As, 100 µM) for 7 days. PS or PMMA caused a reduction in the contents of N, P, K, Ca, Mg and Mn, but the improved contents were detected in the presence of PS or PMMA plus As stress. The hormone contents (auxin, gibberellic acid, cytokinin, salicylic acid and jasmonic acid) reduced by stress were re-arranged through PS or PMMA applications. Based on chlorophyll efficiency, fluorescence kinetics and performance of PSII, the impaired photosynthesis by As stress was improved via PS or PMMA applications. This alleviation did not continue under the combined form of PS and PMMA in As-applied plants. All analyzed antioxidant activity (superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), ascorbate peroxidase (APX), glutathione reductase (GR), glutathione S-transferase (GST), glutathione peroxidase (GPX), monodehydroascorbate reductase (MDHAR) and dehydroascorbate reductase (DHAR)) decreased or unchanged under As, PS or PMMA. Due to the inactivation of the defense system, L. minor had high levels of hydrogen peroxide (H2O2) and thiobarbituric acid reactive substances (TBARS), showing lipid peroxidation. After As toxicity, induvial applications of PS or PMMA indicated the activated enzyme capacity (SOD, POX, GST and GPX) and upregulated AsA/DHA, GSH/GSSG and redox state of GSH, which facilitated the removal of radical accumulation. The efficiency of the antioxidant system in As + PS + PMMA-applied L. minor was not enough to remove damage induced by As stress; hereby, TBARS and H2O2 contents were similar to the As-treated group. Our findings from alone or combined application of PS and PMMA provide new information to advance the tolerance mechanism against As exposure in L. minor.

Hormetic activation of nano-sized rare earth element terbium on growth, PSII photochemistry, antioxidant status and phytohormone regulation in Lemnaminor.

Soils contaminated with rare earth elements (REEs) can damage agriculture by causing physiological disorders in plants which are evaluated as the main connection of the human food chain. A biphasic dose response with excitatory responses to low concentrations and inhibitory/harmful responses to high concentrations has been defined as hormesis. However, not much is clear about the ecological effects and potential risks of REEs to plants. For this purpose, here we showed the impacts of different concentrations of nano terbium (Tb) applications (5-10-25-50-100-250-500 mg L-1) on the accumulation of endogeneous certain ions and hormones, chlorophyll fluoresence, photochemical reaction capacity and antioxidant activity in duckweed (Lemna minor). Tb concentrations less than 100 mg L-1 increased the contents of nitrogen (N), phosphate (P), potassium (K+), calcium (Ca2+), magnesium (Mg2+), manganese (Mn2+) and iron (Fe2+). Chlorophyll fluorescence (Fv/Fm and Fv/Fo) was suppressed under 250-500 mg L-1 Tb. In addition, Tb toxicity affected the trapped energy adversely by the active reaction center of photosystem II (PSII) and led to accumulation of inactive reaction centers, thus lowering the detected level of electron transport from photosystem II (PSII) to photosystem I (PSI). On the other hand, 5-100 mg L-1 Tb enhanced the activities of superoxide dismutase (SOD), catalase (CAT), peroxidase (POX), NADPH oxidase (NOX), ascorbate peroxidase (APX), glutathione reductase (GR), monodehydroascorbate reductase (MDHAR), dehydroascorbate reductase (DHAR) and glutathione S-transferase (GST). Tb (5-50 mg L-1) supported the maintenance of cellular redox status by promoting antioxidant pathways involved in the ascorbate-glutathione (AsA-GSH) cycle. In addition to the antioxidant system, the contents of some hormones such as indole-3-acetic acid (IAA), gibberellic acid (GA), cytokinin (CK) and salicylic acid (SA) were also induced in the presence of 5-100 mg L-1 Tb. In addition, the levels of hydrogen peroxide (H2O2) and lipid peroxidation (TBARS) were controlled through ascorbate (AsA) regeneration and effective hormonal modulation in L. minor. However, this induction in the antioxidant system and phytohormone contents could not be resumed after applications higher than 250 mg L-1 Tb. TBARS and H2O2, which indicate the level of lipid peroxidation, increased. The results in this study showed that Tb at appropriate concentrations has great potential to confer tolerance of duckweed by supporting the antioxidant system, protecting the biochemical reactions of photosystems and improving hormonal regulation.

Multiwalled Carbon Nanotubes Alter the PSII Photochemistry, Photosystem-Related Gene Expressions, and Chloroplastic Antioxidant System in Zea mays under Copper Toxicity.

A critical approach against copper (Cu) toxicity is the use of carbon nanomaterials (CNMs). However, the effect of CNMs on Cu toxicity-exposed chloroplasts is not clear. The photosynthetic, genetic, and biochemical effects of multiwalled carbon nanotubes (50-100-250 mg L-1 CNT) were investigated under Cu stress (50-100 µM CuSO4) in Zea mays chloroplasts. Fv/Fm and Fv/Fo were suppressed under stress. Stress altered the antioxidant system and the expression of psaA, psaB, psbA, and psbD. The chloroplastic activities of superoxide dismutase (SOD), ascorbate peroxidase (APX), glutathione S-transferase (GST), and glutathione peroxidase (GPX) increased under CNT + stress, and those of hydrogen peroxide (H2O2) and lipid peroxidation decreased. CNTs were promoted to the maintenance of the redox state by regulating enzyme/non-enzyme activity/contents involved in the AsA-GSH cycle. Furthermore, CNTs inverted the negative effects of Cu by upregulating the transcriptions of photosystem-related genes. However, the high CNT concentration had adverse effects on the antioxidant capacity. CNT has great potential to confer tolerance by reducing Cu-induced damage and protecting the biochemical reactions of photosynthesis.

Fe2O3-modified graphene oxide mitigates nanoplastic toxicity via regulating gas exchange, photosynthesis, and antioxidant system in Triticum aestivum.

The ever-increasing plastic pollution in soil and water resources raises concerns about its effects on terrestrial plants and agroecosystems. Although there are many reports about the contamination with nanoplastics on plants, the presence of magneto-assisted nanomaterials enabling the removal of their adverse impacts still remains unclear. Therefore, the purpose of the current study is to evaluate the potential of nanomaterial Fe2O3-modified graphene oxide (FGO, 50-250 mg L-1) to eliminate the adverse effects of nanoplastics in plants. Wheat plants exposed to polystyrene nanoplastics concentrations (PS, 10, 50 and 100 mg L-1) showed decreased growth, water content and loss of photosynthetic efficiency. PS toxicity negatively altered gas exchange, antenna structure and electron transport in photosystems. Although the antioxidant system was partially activated (only superoxide dismutase (SOD), NADPH oxidase (NOX) and glutathione reductase (GR)) in plants treated with PS, it failed to prevent PS-triggered oxidative damage, as showing lipid peroxidation and hydrogen peroxide (H2O2) levels. FGOs eliminated the adverse impacts of PS pollution on growth, water status, gas exchange and oxidative stress markers. In addition, FGOs preserve the biochemical reactions of photosynthesis by actively increasing chlorophyll fluorescence parameters in the stressed-wheat leaves. The activities of all enzymatic antioxidants increased, and the H2O2 and TBARS contents decreased. GSH-mediated detoxifying antioxidants such as glutathione S-transferase (GST) and glutathione peroxidase (GPX) were stimulated by FGOs against PS pollution. FGOs also triggered the enzymes and non-enzymes related to the Asada-Halliwell cycle and protected the regeneration of ascorbate (AsA) and glutathione (GSH). Our findings indicated that FGO had the potential to mitigate nanoplastic-induced damage in wheat by regulating water relations, protecting photosynthesis reactions and providing efficient ROS scavenging with high antioxidant capacity. This is the first report on removing PS-induced damage by FGO applications in wheat leaves.

Polystyrene nanoplastic contamination mixed with polycyclic aromatic hydrocarbons: Alleviation on gas exchange, water management, chlorophyll fluorescence and antioxidant capacity in wheat.

Polycyclic aromatic hydrocarbons (PAHs) constitute a significant environmental pollution group that reaches toxic levels with anthropogenic activities. The adverse effects of nanoplastics accumulating in ecosystems with the degradation of plastic wastes are also a growing concern. Previous studies have generally focused on the impact of single PAH or plastic fragments exposure on plants. However, it is well recognized that these contaminants co-exist at varying rates in agricultural soil and water resources. Therefore, it is critical to elucidate the phytotoxicity and interaction mechanisms of mixed pollutants. The current study was designed to comparatively investigate the single and combined effects of anthracene (ANT, 100 mg L-1), fluorene (FLU, 100 mg L-1) and polystyrene nanoplastics (PS, 100 mg L-1) contaminations in wheat. Plants exposed to single ANT, FLU and PS treatments demonstrated decline in growth, water content, high stomatal limitations and oxidative damage. The effect of ANT + FLU on these parameters was more detrimental. In addition, ANT and/or FLU treatments significantly suppressed photosynthetic capacity as determined by carbon assimilation rate (A) and chlorophyll a fluorescence transient. The antioxidant system was not fully activated (decreased superoxide dismutase, peroxidase and glutathione reductase) under ANT + FLU, then hydrogen peroxide (H2O2) content (by 2.7-fold) and thiobarbituric acid reactive substances (TBARS) (by 2.8-fold) increased. Interestingly, ANT + PS and FLU + PS improved the growth, water relations and gas exchange parameters. The presence of nanoplastics recovered the adverse effects of ANT and FLU on growth by protecting the photosynthetic photochemistry and reducing oxidative stress. PAH plus PS reduced the ANT and FLU accumulation in wheat leaves. In parallel, the increased antioxidant system, regeneration of ascorbate, glutathione and glutathione redox status observed under ANT + PS and FLU + PS. These findings will provide an information about the phytotoxicity mechanisms of mixed pollutants in the environment.

The impacts of nanoplastic toxicity on the accumulation, hormonal regulation and tolerance mechanisms in a potential hyperaccumulator - Lemna minor L.

Plastic pollution, which is currently one of the most striking problems of our time, raises concerns about the dispersal of micro and nano-sized plastic particles in ecosystems and their toxic effects on living organisms. This study was designed to reveal the toxic effects of polystyrene nanoplastic (PS NP) exposure on the freshwater macrophyte Lemna minor. In addition, elucidating the interaction of this aquatic plant, which is used extensively in the phytoremediation of water contaminants and wastewater treatment facilities, with nanoplastics will guide the development of remediation techniques. For this purpose, we examined nanoplastic accumulation, oxidative stress markers, photosynthetic efficiency, antioxidant system activity and phytohormonal changes in L. minor leaves subjected to PS NP stress (P-1, 100 mg L-1; P-2, 200 mg L-1 PS NP). Our results showed no evidence of PS NP-induced oxidative damage in P-1 group plants, although PS NP accumulation reached 56 µg g-1 in the leaves. Also, no significant changes in chlorophyll a fluorescence parameters were observed in this group, indicating unaffected photosynthetic efficiency. PS NP exposure triggered the antioxidant system in L. minor plants and resulted in a 3- and 4.6-fold increase in superoxide dismutase (SOD) activity in the P-1 and P-2 groups. On the other hand, high-dose PS NP treatment resulted in insufficient antioxidant activity in the P-2 group and increased hydrogen peroxide (H2O2) and lipid peroxidation (TBARS contents) by 25 % and 17 % compared to the control plants. Furthermore, PS NP exposure triggered abscisic acid biosynthesis (two-fold in the P-1 and three-fold in the P-2 group), which is also involved in regulating the stress response. In conclusion, L. minor plants tolerated NP accumulation without growth suppression, oxidative stress damage and limitations in photosynthetic capacity and have the potential to be used in remediation studies of NP-contaminated waters.

The hormetic dose-risks of polymethyl methacrylate nanoplastics on chlorophyll a fluorescence transient, lipid composition and antioxidant system in Lactuca sativa.

Nanoplastic pollution has become an increasing problem due to over-consumption and degradation in ecosystems. A little is known about ecological toxicity and the potential risks of nanoplastics on plants. To better comprehend the hormetic effects of nanoplastics, the experimental design was conducted on the impacts of polymethyl methacrylate (PMMA) on water status, growth, gas exchange, chlorophyll a fluorescence transient, reactive oxygen species (ROS) content (both content and fluorescence visualization), lipid peroxidation and antioxidant capacity (comparatively between leaves and roots). For this purpose, PMMA (10, 20, 50 and 100 mg L-1) was hydroponically applied to Lactuca sativa for 15 days(d). PMMA exposure resulted a decline in the growth, water content and osmotic potential. As based on assimilation rate (A), stomatal conductance (gs), and intercellular CO2 concentrations (Ci), the decreased stomatal limitation (Ls) and, A/Ci and increased intrinsic mesophyll efficiency proved low carboxylation efficiency showing impaired photosynthesis as a non-stomatal limitation. PMMA toxicity increased the trapping fluxes and absorption with a decrease in electron transport fluxes caused the disruption in reaction centers of photosystems. The leaves and roots had a similar effect against PMMA toxicity, with increased superoxide dismutase (SOD) activity. Although, catalase (CAT) and peroxidase (POX) of leaves increased under 10 mg L-1 PMMA, these defense activities failed to prevent radicals from attacking. Compared to the leaves, the lettuce roots showed an intriguing result for AsA-GSH cycle against PMMA exposure. In the roots, the lowest PMMA application provided the high ascorbate/dehydroascorbate (AsA/DHA), GSH/GSSG and the pool of AsA/glutathione (GSH) and non-suppressed GSH redox state. Also, 10 mg L-1 PMMA helped remove high hydrogen peroxide (H2O2) by both glutathione peroxidase (GPX) and glutathione S-transferase (GST). Since this improvement in the antioxidant system could not be continued in roots after higher applications than 20 mg L-1 PMMA, TBARS (Thiobarbituric acid-reactive substances), indicating the level of lipid peroxidation, and H2O2 increased. Our findings obtained from PMMA-applied lettuce provide new information to advance the tolerance mechanism against nanoplastic pollution.

The effects of fullerene on photosynthetic apparatus, chloroplast-encoded gene expression, and nitrogen assimilation in Zea mays under cobalt stress.

Carbon nanostructures, such as the water-soluble fullerene (FLN) derivatives, are considered perspective agents for agriculture. FLN can be a novel nano-agent modulating plant response against stress conditions. However, the mechanism underlying the impacts of FLN on plants in agroecosystems remains unclear. Zea mays was exposed to exogenous C60 -FLN applications (FLN1: 100; FLN2: 250; and FLN3: 500 mg L-1 ) with/without cobalt stress (Co, 300 µM) for 3 days (d). In the maize chloroplasts, Co stress disrupted the photosynthetic efficiency and the expression of genes related to the photosystems (psaA and psbA). FLNs effectively improved the efficiency and photochemical reaction of photosystems. Co stress induced the accumulation of reactive oxygen species (ROS) as confirmed by ROS-specific fluorescence in guard cells. Co stress increased only chloroplastic superoxide dismutase (SOD) and peroxidase (POX). Stress triggered oxidative damages in maize chloroplasts, measured as an increase in TBARS content. In Co-stressed seedlings exposed to FLN1 and FLN2 exposures, the hydrogen peroxide (H2 O2 ) was scavenged through the nonenzymes/enzymes-related to the AsA-GSH cycle by preserving ascorbate (AsA) conversion, as well as GSH/GSSG and glutathione (GSH) redox state. Also, the alleviation effect of FLN3 against stress could be attributed to increased glutathione S-transferase (GST) activity and AsA regeneration. FLN applications reversed the inhibitory effects of Co stress on nitrogen assimilation. In maize chloroplasts, FLN increased the activities of nitrate reductase (NR), glutamate dehydrogenase (GDH), nitrite reductase (NiR), and glutamine synthetase (GS), which provided conversion of inorganic nitrogen (N) into organic N. The ammonium (NH4 + ) toxicity was removed via GS and GDH but not glutamate synthase (GOGAT). The increased NAD-GDH (deaminating) and NADH-GDH (aminating) activities indicated that GDH was needed more for NH4 + detoxification. Therefore, FLN exposure to Co-stressed maize plants might play a role in N metabolism regarding the partitioning of N assimilates. Exogenous FLN conceivably removed Co toxicity by improving the expressions of genes related to reaction center proteins of photosystems, increasing the level of enzymes related to the defense system, and improving the N assimilation in maize chloroplasts.

The biphasic responses of nanomaterial fullerene on stomatal movement, water status, chlorophyll a fluorescence transient, radical scavenging system and aquaporin-related gene expression in Zea mays under cobalt stress.

Nanomaterial fullerene (FLN) has different responses called the hormesis effect against stress conditions. The favorable/adverse impacts of hormesis on crop quality and productivity are under development in agrotechnology. In this study, the effect of FLN administration (100-250-500mg L-1 for FLN1-2-3, respectively) on growth, water management, gas exchange, chlorophyll fluorescence kinetics and cobalt (Co)-induced oxidative stress in Zea mays was investigated. The negative alterations in relative growth rate (RGR), water status (relative water content, osmotic potential and proline content) and gas exchange/stomatal regulation were removed by FLNs. FLNs were shown to protect photosynthetic apparatus and preserve the photochemistry of photosystems (PSI-PSII) in photosynthesis, chlorophyll fluorescence transients and energy flux damaged under Co stress. The maize leaves exposed to Co stress exhibited a high accumulation of hydrogen peroxide (H2O2) due to insufficient scavenging activity, which was confirmed by reactive oxygen species (ROS)-specific fluorescence visualization in guard cells. FLN regulated the gene expression of ribulose-1,5-bisphosphate carboxylase large subunit (rbcL), nodulin 26-like intrinsic protein1-1 (NIP1-1) and tonoplast intrinsic protein2-1 (TIP2-1) under stress. After stress exposure, FLNs successfully eliminated H2O2 content produced by superoxide dismutase (SOD) activity of catalase (CAT) and peroxidase (POX). The ascorbate (AsA) regeneration was achieved in all FLN applications together with Co stress through the elevated monodehydroascorbate reductase (MDHAR, under all FLNs) and dehydroascorbate reductase (DHAR, only FLN1). However, dose-dependent FLNs (FLN1-2) provided the induced pool of glutathione (GSH) and GSH redox state. Hydroponically applied FLNs removed the restrictions on metabolism and biological process induced by lipid peroxidation (TBARS content) and excessive ROS production. Considering all data, the modulation of treatment practices in terms of FLN concentrations and forms of its application will provide a unique platform for improving agricultural productivity and stress resistance in crops. The current study provided the first findings on the chlorophyll a fluorescence transient and localization of ROS in guard cells of Zea mays exposed to FLN and Co stress.

Nanomaterial sulfonated graphene oxide advances the tolerance against nitrate and ammonium toxicity by regulating chloroplastic redox balance, photochemistry of photosystems and antioxidant capacity in Triticum aestivum.

The current study was designed to assess nanomaterial sulfonated graphene oxide (SGO) potential in improving tolerance of wheat chloroplasts against nitrate (NS) and ammonium (AS) toxicity. Triticum aestivum cv. Ekiz was grown under SGOs (50-250-500 mg L-1) with/without 140 mM NS and 5 mM AS stress. SGOs were eliminated the adverse effects produced by stress on chlorophyll fluorescence, potential photochemical efficiency and physiological state of the photosynthetic apparatus. SGO reversed the negative effects on these parameters. Upon SGOs exposure, the induced expression levels of photosystems-related reaction center proteins were observed. SGOs reverted radical accumulation triggered by NS by enabling the increased superoxide dismutase (SOD) activity and ascorbate (AsA) regeneration. Under AS, the turnover of both AsA and glutathione (GSH) was maintained by 50-250 mg L-1 SGO by increasing the enzymes and non-enzymes related to AsA-GSH cycle. 500 mg L-1 SGO prevented the radical over-accumulation produced by AS via the regeneration of AsA and peroxidase (POX) activity rather than GSH regeneration. 50-250 mg L-1 SGO protected from the NS+AS-induced disruptions through the defense pathways connected with AsA-GSH cycle represented the high rates of AsA/DHA and, GSH/GSSG and GSH redox state. Our findings specified that SGO to NS and AS-stressed wheat provides a new potential tool to advance the tolerance mechanism.

Surgical treatment and outcomes of intramedullary tumors by minimally invasive approach: Answer.

The surgical outcomes which evaluated in studies depend on preoperative condition, demographic data of patients, surgical approaches or treatment and local factors. Author argues that the neurological deterioration rate 4,2% which is reported in our study is marvelous and he exemplifies the other studies in literature. Neurosurgeons know that the clinical studies in literature do not compare only their results. Authors compare and evaluate studies with preoperative demographic data, surgical approach, local factors or others between their results. Therefore this detail explains paralogism of the author. The neurological deterioration rate is reported as smaller or similar in our study to the contrary of others due to all the preoperative demographical data were evaluated with others. We suppose the author alludes that the neurological deterioration rate is marvelous since he does not compare all of the demographical data in these clinical studies.

Surgical treatment and outcomes of intramedullary tumors by minimally invasive approach.

Intramedullary tumors are uncommon neoplasms which, without treatment, can cause neurologic morbidity or mortality. The goal of the treatment is complete surgical resection with a minimally invasive approach while preserving neurological status and also spinal stability. Out of 1972 patients with tumors of the spinal canal treated between 1994 and 2017, 168 intramedullary tumors of 417 intradural tumors have been presented. All patients had undergone one surgical resection. The mean age is 43 ± 12 years (range 11-67 years). Tumors were subdivided into 4 groups: cervically located-tumors (n = 43), cervicothoracic-region-tumors (n = 32), thoracic-region-tumors (n = 57), and lumbosacral-region-tumors (n = 36). The mean follow-up time was 37 ± 29 months. Gross-total resection rate was higher in cervical located intramedullary tumors compared to the thoracic intramedullary tumors. Cervical intramedullary tumors showed better postoperative functional outcome than the thoracic intramedullary lesions. In intramedullary tumors, extending more than 3 spinal segments, postoperative worsening was significantly increased. A minimally invasive approach (the bilateral decompression via unilateral hemilaminectomy) was used to remove the tumor while preserving spinal stability. Perioperative permanent morbidity was very low. Intramedullary tumors should be surgically treated as soon as neurological symptoms appear. Patients with thoracic intramedullary tumors and tumor extension of more than three segments were at a higher risk for permanent morbidity. The minimally invasive approach allowed complete removal of the intramedullary tumors, and adequate preservation of vertebral stability while providing a good postoperative course.

Surgical Outcomes of Extraforaminal Microdiskectomy by Midline Incision for Far-Lateral Lumbar Disk Herniation.

BACKGROUND: Far-lateral lumbar disk herniation (FLDH) is defined as a disk herniation located laterally to the medial wall of the pedicle. The aim of our study is to describe the extraforaminal microdiskectomy by midline incision for FLDH, which does not include laminotomy-partial facetectomy, and to evaluate mid-term surgical outcomes. METHODS: 107 patients who underwent surgery for FLDH by midline incision for the first time between 2012 and 2017 were included in our study. The assessment of neurological status of the patients was done by physical examination, preoperative Oswestry Disability Index (ODI), Visual Analog Scala (VAS) scores, and magnetic resonance images. They were then followed-up postoperatively and at 12 months with VAS and ODI tests. RESULT: 58 (54.2%) patients were male and 49 (45.8%) were female. The mean age at the time of surgery was 55.0 ± 8.6 years. The mean ODI scale score was 32.4 ± 6.2 preoperatively, 11.4 ± 2.1 early postoperatively, and 9.7 ± 2.2 in late postoperative follow-up (statistically significant, p = 0.001). The average VAS was 7.51 ± 1.1 preoperatively, 2.74 ± 0.7 early postoperatively, and 0.68 ± 0.08 in late postoperative follow-up (statistically significant, p = 0.001). The average operative time was 41 ± 7 (37 to 58) minutes. CONCLUSIONS: The extraforaminal microdiskectomy without laminotomy by midline incision is a minimally invasive approach for FLDH. Our technique allows a sufficient and safe decompression of the neural structures, and thus results in a significant reduction of the symptoms and disability.

Diagnosis and Treatment of Transforaminal Epidural Steroid Injection in Lumbar Spinal Stenosis.

OBJECTIVES: Transforaminal epidural steroid injection reduces the low back-leg pain and enables daily activities of the patients. In this study, we aim to evaluate the treatment of transforaminal epidural steroid injection for lumbar spinal stenosis, which was mainly performed for lumbar disc herniation and share our diagnostic experience for lumbar spinal stenosis which is treated surgically. METHODS: In our study, 37 patients were included who were treated by transforaminal epidural steroid injection for Grade B lumbar spinal stenosis in our clinic between June-2014 and June-2018. We evaluated the patients at the second weeks, third/sixth months and one year after the treatment by Oswestry-Disability-Index and Visual-Analogue-Scale and followed up for surgical treatment after one year. RESULTS: The mean low back and leg pain Visual Analogue Scale was 5.1±0.3 before the transforaminal epidural steroid injection procedure, and it was 2.7±0.1 after two weeks. It was 2.8±0.2, 3.1±0.1 at three and six months after procedure, respectively. The improvement of low back-leg pain mean Visual-Analogue-Scale is statistically significant at two weeks, three and six months after transforaminal epidural steroid injection procedure, respectively. The mean Oswestry-Disability-Index was 29.6±0.4 before the transforaminal epidural steroid injection procedure, and it was 14.1±0.3 after two weeks. It was 15.3±0.5, 24.4±0.2 at three and six months after procedure, respectively. The improvement of Oswestry-Disability-Index is statistically significant at two weeks, three-six months. CONCLUSION: The transforaminal epidural steroid injection is safe procedure for non-surgical treatment of lumbar spinal stenosis and this procedure may be preferred support to the indication of the surgical treatment of level of lumbar spinal stenosis.

Ultrasound-Guided Microsurgical Excision for Brachial Plexus Schwannomas: Short-Term Clinical Study.

AIM: To describe the ultrasound-guided microsurgical excision technique and to evaluate the surgical outcomes of brachial plexus schwannomas. MATERIAL AND METHODS: Eleven patients who underwent ultrasound-guided microsurgery for small ( < 3 cm) brachial plexus schwannomas between 2013 and 2017 were included in our study. RESULTS: The mean age of the patients was 45 years (range: 30-68 years), with six tumors localized on the right and five on the left side. There were no perioperative or postoperative complications. No postoperative deficits were observed in the patients. CONCLUSION: Surgeons can safely and completely excise most of the benign ( < 3 cm and non-palpable) brachial plexus tumors by the ultrasound-guided microsurgical excision technique.

Surgical outcome and efficacy of lumbar microdiscectomy technique with preserving of ligamentum flavum for recurrent lumbar disc herniations.

The reoperation for recurrent lumbar disc herniation (LDH) causes difficulties and low surgical outcome. The operation technique which was preferred in the first surgery has gained importance in reoperation for recurrent-LDH. The aim of our study is to evaluate the efficacy of lumbar microdiscectomy technique with preserving of ligamentum flavum (LF) for recurrent lumbar disc surgery. 149 patients were evaluated in two groups in our study, who were treated for single level recurrent-LDH in our clinic. The first group contains 86 patients who were treated by lumbar microdiscectomy without preserving LF during first surgery in other clinics, the second group contains 63 patients who were treated by lumbar microdiscectomy with preserving of LF during first surgery in our clinic. We investigated age, weight, gender, recurrence-time, level-side of recurrent-LDH, the surgical outcomes and hemorrhage, complications, operation-time. The mean-age was 45,9 ±â€¯12,9, 44,1 ±â€¯11,6 years and mean-weight was 73,4 ±â€¯14,4, 77,3 ±â€¯14,2 kg in two groups. 29 patients were treated for L3-4, 63 patients for L4-5, 57 patients were treated for L5-S1 recurrent LDH. The preoperative and follow-up back-leg pain Visual Analogue Scale (VAS), Oswestry Disability Index (ODI) scores decreased significantly in all patients (p < 0,05). The average operation-time was 70,9 ±â€¯5,2 and 42,3 ±â€¯4,6 min and the average surgical hemorrhage was 91,1 ±â€¯11,3 and 50,3 ±â€¯7,4 ml in 1. group and 2. group respectively. Preserving of LF in first surgery is gaining importance for recurrent lumbar disc surgery with protected anatomical structures. Our technique decreases complication, operation time, surgical hemorrhage and provides good surgical outcomes in recurrent lumbar disc surgery.

Long-Term Clinical Outcome and Reoperation Rate for Microsurgical Bilateral Decompression via Unilateral Approach of Lumbar Spinal Stenosis.

OBJECTIVE: To evaluate long-term outcome and reoperation rate for microsurgical bilateral decompression via unilateral approach of lumbar spinal stenosis, a common degenerative spinal disease of the lumbar spine. METHODS: In this observational prospective study, 918 patients were treated for single-level or multilevel lumbar spinal stenosis by bilateral decompression via unilateral approach between January 2002 and January 2016. Of 918 patients, 180 underwent microdiscectomy with decompression. Follow-up consisted of radiologic investigations, Oswestry Disability Index questionnaire, and 36-Item Short-Form Health Survey at 6 and 12 months postoperatively. RESULTS: There were 492 female patients (53.6%) and 426 male patients (46.4%) with a mean age of 63.83 ± 10.16 years (range, 43-79 years). Symptom duration was 4-49 months. Average follow-up time was 98 months (range, 25-168 months), and reoperation rate was 2.5%. Oswestry Disability Index scores decreased significantly (from 30.65 ± 7.82 to 11.32 ± 2.50 at 6 months and 11.30 ± 2.49 at 12 months), and 36-Item Short-Form Health Survey parameter scores demonstrated a significant improvement in the early and late follow-up results. CONCLUSIONS: Bilateral decompression via unilateral approach for lumbar spinal stenosis allowed a sufficient and safe decompression of the neural structures, resulting in a highly significant reduction of symptoms and disability, acceptable reoperation rate, and improved health-related quality of life.