Magnetic Studies Research Articles

Recent advances in solid‐state nuclear magnetic resonance studies on membrane fusion proteins

Membrane fusion is an essential biological process that merges two separate lipid bilayers into a whole one. Membrane fusion proteins facilitate this process by bringing lipid bilayers in close proximity to reduce the repulsive energy between membranes. Along with their interactions with membranes, the structures and dynamics of membrane fusion proteins are key to elucidating the mechanisms of membrane fusion. Solid‐state NMR (SSNMR) spectroscopy has unique advantages in determining the structures and dynamics of membrane fusion proteins in their membrane‐bound states. It has been extensively applied to reveal conformational changes in intermediate states of viral membrane fusion proteins and to characterize the critical lipid–membrane interactions that drive the fusion process. In this review, we summarize recent advancements in SSNMR techniques for studying membrane fusion proteins and their applications in elucidating the mechanisms of membrane fusion.

Practical magneto-optical imaging of the current density of coated conductors within liquid nitrogen

Magneto-optical imaging (MOI) is widely used for magnetic studies of superconducting materials due to its advantages of full-field, real-time operation and high resolution. However, a traditional MOI system requires vacuum pumping, thermal shielding, and cooling by thermal conducting, thereby making the system very complex and expensive and increasing the time required to complete a set of experiments. In this study, a novel (to our knowledge) and practical approach for MOI within liquid nitrogen (LN) is proposed in which thermal conducting, thermal shielding, and vacuum pumping are no longer necessary. The key technique is realized through a semi-immersed polymethyl methacrylate (PMMA) bar in LN, and its size is optimized to ensure a stable temperature difference and polarized optical visualization within LN. With the improvised method, a defect in a superconducting layer of length approximately 250 µm in the coated conductor (CC) sample was detected. Additionally, the current density reduced by approximately 50% in magnitude compared to its neighbor region, thus demonstrating the effectiveness of the new approach. It is expected that this technique can further enhance the application of MOI as an efficient tool for industrial inspection of superconducting CCs.

The Impact of Coordination Distortion on Magnetic Properties of Co (II) Single‐Ion Magnets With Trigonal Prism Coordination Geometry

ABSTRACTTwo Co (II) compounds [Co (abs)2]·2H2O (1) and [Co (pabs)2] (2) (Habs = N‐(pyridine‐2′‐yl methylene)‐2‐aminobenzene sulfonic acid, Hpabs = N‐[(pyridine‐2′‐yl)(phenyl)methylene]‐2‐aminobenzene sulfonic acid) were synthesized by the introduction of sulfonate ligands with different substitutions. Both Co (II) ions are located in a trigonal prism coordination environment with different coordination distortions. Static magnetic studies and theoretical calculations found that easy‐axis magnetic anisotropy is present in both complexes. The contributions of the negative D values are principally derived from the first quartet excited state. Dynamic magnetic investigations uncovered that both compounds have field‐induced single‐ion magnet (SIM) behavior and their magnetic relaxations mainly realize through Raman and direct pathways.

Altered parasympathetic outflow and central sensitization response to continuous pain in cyclic vomiting syndrome: a functional magnetic resonance imaging study.

Cyclic vomiting syndrome (CVS) is a disorder of brain-gut interaction characterized by recurrent episodes of nausea and vomiting interspersed with asymptomatic periods and associated with autonomic nervous system dysfunction. We examined the dysautonomic response to noxious stimuli seen in CVS patients using our previously validated approach to integrate peripheral autonomic outflow metrics, temporal summation of pain, and brain fMRI. BOLD fMRI and ECG were acquired from CVS patients and healthy adults during a rest condition and a sustained cuff pressure pain stimulus at the leg. After the latter scan, participants rated pain for the full 6-minute pain stimulus as well as first, middle, and last two-minutes to calculate temporal summation. During sustained pain, patients (n=13) exhibited greater reduction in heart rate variability within the high-frequency range (HF-HRV) and reduced anticorrelation between HF-HRV and fMRI signal in the anterior insula, pregenual anterior cingulate cortex, and ventrolateral and dorsolateral prefrontal cortex relative to healthy adults (n=13). Compared to healthy adults (n=14), patients (n=14) exhibited increasing pain intensity over the course of sustained cuff pressure. Seed-based functional connectivity analysis revealed for healthy adults (n=13), pain sensitization correlated with pain-induced increases in connectivity between primary somatosensory cortex and regions of interest in both left anterior insula/posterior orbitofrontal cortex and right pre-supplementary motor area, while this correlation was disrupted in CVS (n=10). Our results support altered central coding of nociceptive stimuli and autonomic responsivity of CVS patients in key brain regions implicated in autonomic control and interoception.

Assessment of All-Inside Sutures to the Posteromedial Capsule in Medial Meniscus Posterior Root Repair: Findings From a Retrospective Three-Dimensional Magnetic Resonance Imaging Study

Assessment of All-Inside Sutures to the Posteromedial Capsule in Medial Meniscus Posterior Root Repair: Findings From a Retrospective Three-Dimensional Magnetic Resonance Imaging Study

Case Report: Periocular Steroid Injection Combined Vemurafenib Therapy in the Long-term Management of Orbital Involvement of Erdheim-Chester Disease.

Abstract Purpose: To report a rare case of vision loss from Erdheim-Chester Disease (ECD) and long term, follow up, management and results. Case Report: A 62-year-old woman presented with bilateral exophthalmos and deterioration in visual acuity of both eyes. Magnetic resonance imaging studies revealed bilateral intraconal orbital tumors. She was diagnosed optic neuropathy in both eyes. The patient was treated with pegylated interferon and systemic pulse steroid. However, recurrences were common. Subsequently, the patient underwent regular corticosteroid injection directly into the retro-orbital region of both eyes monthly, which led to intermittent improvement of vision. At the 8th month of visual impairment, Vemurafenib was initiated. Results: The visual acuity and visual field scores were stable for 6 years during the follow-up. No major complication was observed. Conclusion: Combined vemurafenib and perioculer steroid injection is a well tolerated therapy with less systemic adverse effects which may benefit patients with orbital involvement of ECD. Key words: Erdheim–Chester disease; compressive optic neuropathy; vemurafenib; Optical coherence tomography; Optical coherence tomography angiography.

The Added Value of Apparent Diffusion Coefficient and Histogram Analysis in Assessing Treatment Response of Locally Advanced Cervical Cancer

Objective The aim of the study is to assess the diagnostic performance of quantitative analysis of diffusion-weighted imaging in assessing treatment response in cervical cancer patients. Methods A retrospective analysis was done for 50 patients with locally advanced cervical cancer who received concurrent chemoradiotherapy and underwent magnetic resonance imaging and diffusion-weighted imaging. Treatment response was classified into 4 categories according to RECIST criteria 6 months after therapy completion. Apparent diffusion coefficient (ADC) values were measured using both region of interest (ROI) ADC and whole lesion (WL) ADC histogram for all cases at both baseline pretreatment and posttreatment Magnetic resonance imaging studies. Changes in ADC values were calculated and compared between groups. Results The percentage change of ROI-ADCmean at a cutoff value of >20 had excellent discrimination of responders versus nonresponders, while the percentage change of WL-ADCmean, ADCmin, and ADCmax at cutoff values of >12.5, >35.8, and > 19.6 had acceptable discrimination of responders versus nonresponders. Logistic regression analysis revealed that only baseline WL ADCmin was a statistically significant independent predictor of response. Cancer cervix patients with baseline ADCmin < or equal to 0.73 have 12.1 times higher odds of exhibiting a response. Conclusions The percentage change of ROI-ADCmean and WL histogram ADCmean values after concurrent chemoradiotherapy can predict response. Pretreatment WL histogram ADCmin was a statistically significant independent predictor of posttherapy response.

Experimental investigation on high heat flux plasma parameters of HIT-PSI device in argon discharges

Abstract Researches on plasma-facing materials/components (PFMs/PFCs) have become a focus in magnetic confinement fusion studies, particularly for advanced tokamak operation scenarios. Similarly, spacecraft surface materials must maintain stable performance under relatively high temperatures and other harsh plasma conditions, making studies of their thermal and ablation resistance critical. Recently, a low-cost, low-energy-storage for superconducting magnets, and compact linear device, HIT-PSI, has been designed and constructed at Harbin Institute of Technology (HIT) to investigate the interaction between stable high heat flux plasma and PFMs/PFCs in scrape-off-layer (SOL) and divertor regions, as well as spacecraft surface materials. The parameters of the argon plasma beam of HIT-PSI are diagnosed using a water-cooled planar Langmuir probe and emission spectroscopy. As magnetic field rises to 2 T, the argon plasma beam generated by a cascaded arc source achieves high density exceeding 1.2×1021 m−3 at a distance of 25 cm from the source with electron temperature surpassing 4 eV, where the particle flux reaches 1024 m−2s−1, and the heat flux loaded on the graphite target measured by infrared camera reaches 4 MW/m2. Combined with probe and emission spectroscopy data, the transport characteristics of the argon plasma beam are analyzed.

Neural Correlates of Retrieval Success and Precision: A Functional Magnetic Resonance Imaging Study.

Prior studies examining the neural mechanisms underlying retrieval success and precision have yielded inconsistent results. Here, the neural correlates of success and precision were examined with a memory task that assessed precision for spatial location. A sample of healthy young adults underwent functional magnetic resonance imaging scanning during a single study-test cycle. At study, participants viewed a series of object images, each placed at a randomly selected location on an imaginary circle. At test, studied images were intermixed with new images and presented to the participants. The requirement was to move a cursor to the location of the studied image, guessing if necessary. Participants then signaled whether the presented image had been studied. Memory precision was quantified as the angular difference between the studied location and the location selected by the participant. A precision effect was evident in the left angular gyrus, where BOLD activity covaried with location accuracy. In addition, multivoxel pattern analysis revealed a significant item-level reinstatement effect in the angular gyrus for high-precision trials. There was no evidence of a retrieval success effect in this region. BOLD activity in the hippocampus was insensitive to both success and precision. These findings are partially consistent with prior evidence that success and precision are dissociable features of memory retrieval.

How Can Graph Theory Inform the Dual-stream Model of Speech Processing? A Resting-state Functional Magnetic Resonance Imaging Study of Stroke and Aphasia Symptomology.

The dual-stream model of speech processing describes a cortical network involved in speech processing. However, it is not yet known if the dual-stream model represents actual intrinsic functional brain networks. Furthermore, it is unclear how disruptions after a stroke to the functional connectivity of the dual-stream model's regions are related to speech production and comprehension impairments seen in aphasia. To address these questions, in the present study, we examined two independent resting-state fMRI data sets: (1) 28 neurotypical matched controls and (2) 28 chronic left-hemisphere stroke survivors collected at another site. We successfully identified an intrinsic functional network among the dual-stream model's regions in the control group using functional connectivity. We then used both standard functional connectivity analyses and graph theory approaches to determine how this connectivity may predict performance on clinical aphasia assessments. Our findings provide evidence that the dual-stream model of speech processing is an intrinsic network as measured via resting-state MRI and that functional connectivity of the hub nodes of the dual-stream network defined by graph theory methods, but not overall average network connectivity, is weaker in the stroke group than in the control participants. In addition, the functional connectivity of the hub nodes predicted linguistic impairments on clinical assessments. In particular, the relative strength of connectivity of the right hemisphere's homologues of the left dorsal stream hubs to the left dorsal hubs, versus to the right ventral stream hubs, is a particularly strong predictor of poststroke aphasia severity and symptomology.

Brain functional alternation in patients with systemic sclerosis: a resting-state functional magnetic resonance imaging study

BackgroundNeuropsychiatric manifestations, such as cognitive impairment, are relatively prevalent in systemic sclerosis (SSc) patients. This study aimed to investigate the resting state (RS) functional alternations of SSc patients and the potential influenced factors.MethodsForty-four SSc patients (mean age, 46.3 ± 11.4 years; 40 females) and 19 age and sex comparable healthy volunteers (mean age, 42.6 ± 11.3 years; 16 females) were recruited and underwent RS functional MR imaging (fMRI) and neuropsychological assessments. Functional segregation analysis was performed to calculate the amplitude of low frequency fluctuation (ALFF) and regional homogeneity (ReHo). Functional integration analysis was conducted using group independent component analysis to calculate intra-network and inter-network functional connectivity (FC). The fMRI measurements were compared between SSc patients and healthy volunteers using voxel-based pairwise two-sample t-tests. The correlations between clinical characteristics and fMRI measurements were also analyzed.ResultsCompared to healthy volunteers, SSc patients exhibited significantly decreased ALFF and increased ReHo (all P < 0.01, FWE corrected). SSc patients predominantly showed decreased intra-network and inter-network FC in the auditory network, visual network, default mode network, frontoparietal network and attention network (intra-network FC: P < 0.01, uncorrected, cluster size > 30; inter-network FC: P < 0.05, FDR correction). Furthermore, clinical characteristics including disease duration (r value ranged from − 0.31 to 0.36), elevated erythrocyte sedimentation rate (r = 0.35), Montreal Cognitive Assessment score (r = 0.43), and Hamilton Depression Scale score (r = -0.40) were significantly associated with fMRI measurements (all P < 0.05).ConclusionsSpontaneous activity and functional connectivity alternations can be seen in SSc patients, which are partially associated with neuropsychiatric manifestations and tend to aggravate with disease duration.

Epineural Scarring Visualization and Noninvasive Quantification of a Severe Posttraumatic Complication: An Experimental Magnetic Resonance Neurography Study.

Peripheral nerve scarring is a severe yet common complication following nerve injury or surgery that can lead to impaired nerve function, including chronic pain and sensory or motor deficits. In this study, we aimed to establish high-resolution magnetic resonance neurography (MRN) to accurately visualize and monitor de novo-formed epineural fibrotic adhesions (EFAs) of the sciatic nerve in a rat nerve injury model. Employing an established model to induce overshooting EFA, the study included 3 experimental groups of animals (n = 6 each): a positive control group (PC), an intervention group (IG), and a sham group. All groups underwent surgical nerve exposure: both PC and IG received an application of 10 μL 2.5% glutaraldehyde to induce EFA, but only IG received an additional preventive wrapping of the nerve with a collagen-containing matrix. Magnetic resonance imaging was performed 6, 8, and 12 weeks postoperatively using a standardized protocol including T2w and T1w without and with contrast media. Motor function and nerve regeneration was assessed using the visual static sciatic index. Histological specimens were obtained 12 weeks postoperatively and correlated with imaging. On high-resolution MRN, prominently contrast-enhancing epineural sleeves were present in vivo, which corresponded to histologically confirmed EFA (ratio of EFA to nerve area MRN 1.512 ± 0.106 vs histological ratio 1.459 ± 0.208, nonsignificant). As expected, average EFA in IG (0.310 ± 0.118 mm2) was smaller than in PC (0.909 ± 0.212 mm2, P < 0.01). Also, the average EFA in sham (0.386 ± 0.030 mm2) was less pronounced than in PC (P < 0.01). There was no significant difference in the average EFA between IG und sham. The EFA correlated with the functional outcome, which was measured by visual static sciatic index (correlation coefficient -0.59, P < 0.05). The results of the present study for the first time confirm the clinical observation that epineural thickening on contrast-enhanced T1w imaging following manipulation to a nerve indeed corresponds to overshooting epineural scarring, which may be linked to impaired nerve function. This can be followed noninvasively in vivo over time providing an important basis for clinical decision-making in cases where further invasive therapies may be necessary.

Structural Effect of N-7 Alkylation in 6-Chloropurine on Cu (II) Binding: Effect of Anions and Magnetic Studies.

This study investigates the anion-directed assembly of discrete copper (II) complexes. The ligands of choice are two N7-alkyl-purine-based neutral ligands. These ligands facilitate the exclusive coordination through the N3 and N9 positions, preventing polymeric chain formation. Perchlorate ions promoted the formation of discrete paddlewheel-like complexes with the general formula [Cu2(μ-Pur)4(CH3CN)2]4+, while chloride ions yielded chloride-bridged dimers of the form [Cu2(Pur)2(μ-Cl)2Cl2]. Copper-copper bond distances within these complexes ranged from 2.92 to 2.98 Å. Magnetic susceptibility measurement of chloride-bridged complexes exhibited antiferromagnetic coupling, whereas paddlewheel complexes displayed more complex alternating ferromagnetic and antiferromagnetic interactions. Chloride-bridged compounds exhibited strong near-infrared absorption.

Predicting analog intrusions from neural correlates of immediate and lasting effects of cognitive reappraisal.

Emotional dysregulation is considered as an etiologically relevant factor for posttraumatic stress disorder. The relevance of immediate and lasting effects of cognitive reappraisal, a prominent emotion regulation strategy, and its habitual use for the development of posttraumatic stress symptoms in response to an experimental trauma are therefore investigated in our study. Eighty-five healthy women participated in a functional magnetic resonance imaging study, which included an emotion regulation paradigm prior to the conduction of the trauma film paradigm, which was used to assess the development of analog intrusions. During the first phase of the emotion regulation paradigm, participants were instructed to use two reappraisal tactics (reinterpretation and distancing) to reduce negative feelings toward aversive pictures or to passively watch aversive and neutral pictures. One week later, these pictures were presented again during a passive reexposure phase. Ratings of negative feelings and blood oxygen level dependent responses in regions of interest served as main outcome variables. The habitual use of cognitive reappraisal was assessed by questionnaire. Reduced habitual use and stronger lasting effects of cognitive reappraisal, as indicated by reduced insula activation during reexposure to pictures previously reinterpreted and distanced from, predicted the development of long-term analog intrusions. Stronger lasting effects of both reappraisal tactics for women with long-term analog intrusions seem to result from stronger emotional reactivity processes. Women with long-term analog intrusions in response to an experimental trauma seem to benefit to a greater extent from a cognitive reappraisal training than women without long-term intrusions. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Synthesis, structure and properties of compounds derived from Kotoite-related structures: A2MB2O6 (A = Zn, Ba, Pb; B = Pb, Ba, Zn, Cu).

A series of compounds with the general formula A2MB2O6 (A = Zn, Ba, Pb; B = Pb, Ba, Zn, Cu) related to the kotoite structure has been prepared employing high-temperature solid state methods. The substitution of transition elements in place of Zn2+ ions resulted in colored compounds. The optical absorption spectra could be explained based on Tanabe-Sugano diagram and allowed d-d transitions. Dielectric studies on Ba2ZnB2O6, (Ba1.5Pb0.5)ZnB2O6, PbZn2B2O6, Pb1.5Zn1.5B2O6, BaZn2B2O6 and Pb2CuB2O6 at room temperature indicate reasonable values at low frequencies, which decrease on increasing frequencies. Magnetic study of synthesized single-phase compounds BaZnCoB2O6 and Pb2CuB2O6 have been performed. The substitution of Eu3+, Tb3+ and Tm3+ in place of Ba2+ in Ba2ZnB2O6, gives rise to the expected emission of red, green and blue colors. Suitable modifications of the different phosphors in Ba2ZnB2O6, resulted in white-light emission in Ba2ZnB2O6. The Pb2CuB2O6 compound was found to be a good catalyst in the ipso-hydroxylation of arylboronic acids.

Controllability of optical, electrical, and magnetic properties of synthesized Cd-doped MgFe2O4 nanostructure

This study explores the synthesis of cadmium-magnesium co-doped magnesium ferrite (Mg1+xCdxFe2–2xO4, 0.00 ≤ x ≤ 0.30, Δx = 0.05) via a citric acid-assisted sol-gel auto-combustion method. X-ray diffraction (XRD) analysis revealed crystal structure changes due to Cd and Mg co-doping, with the 0.25 Cd sample showing the smallest crystallite size and highest lattice strain. High-resolution transmission electron microscopy (HRTEM) confirmed the nanostructure and largest surface area for this sample. Diffuse reflectance spectra, analyzed using the Kubelka-Munk relation, indicated that the 0.25 Cd sample had the lowest energy gap (2.08 eV), supported by band position calculations. Electrical conductivity and charge transport mechanisms were examined at various temperatures. Magnetization studies showed reduced saturation magnetization at x = 0.25, ascribed to cation distribution changes and spin canting, with coercivity and anisotropy decreasing with higher Cd content. Overall, the 0.25 Cd sample exhibited optimized optical, electrical, and magnetic properties due to its distinct microstructure.

Effectiveness of non-invasive brain stimulation on depressive symptoms targeting prefrontal cortex in functional magnetic resonance imaging studies: a combined systematic review and meta-analysis

Abstract The prefrontal cortex (PFC) is a critical non-invasive brain stimulation (NIBS) target for treating depression. However, the alterations of brain activations post-intervention remain inconsistent and the clinical moderators that could improve symptomatic effectiveness are unclear. The study aim was to systematically review the effectiveness of NIBS on depressive symptoms targeting PFC in functional magnetic resonance imaging (fMRI) studies. In our study, we delivered a combined activation likelihood estimation (ALE) meta-analysis and meta-regression. Until November 2020, three databases (PubMed, Web of Science, EMBASE) were searched and fourteen studies with a total sample size of 584 were included in the ALE meta-analysis; after NIBS, four clusters in left cerebrum revealed significant activation while two clusters in right cerebrum revealed significant deactivation (P &amp;lt; 0.001, cluster size &amp;gt; 150 mm3). Eleven studies were statistically reanalyzed for depressive symptoms pre-post active-NIBS and the pooled effect size was very large (d = 1.82, 95%CI [1.23, 2.40]); significant moderators causing substantial heterogeneity (Chi2 = 75.25, P &amp;lt; 0.01; I2 = 87%) were detected through subgroup analysis and univariate meta-regression. Multivariate meta-regression was then conducted accordingly and the model suggested good fitness (Q = 42.32, P &amp;lt; 0.01). In all, NIBS targeting PFC balanced three core depressive-related neurocognitive networks (the salience network, the default mode network and the central executive network); striatum played a central role and might serve as a candidate treatment biomarker; gender difference, treatment-resistant condition, comorbidity, treatment duration and localization all contributed to moderating depressive symptoms during NIBS. More high-quality, multi-center randomized controlled trails delivering personalized NIBS are urged for clinical practice in the future.

Brain-based correlates of depression and traumatic brain injury: a systematic review of structural and functional magnetic resonance imaging studies

IntroductionDepression is prevalent after traumatic brain injury (TBI). However, there is a lack of understanding of the brain-based correlates of depression post-TBI. This systematic review aimed to synthesize findings of structural and functional magnetic resonance imaging (MRI) studies to identify consistently reported neural correlates of depression post-TBI.MethodsA search for relevant published studies was conducted through OVID (MEDLINE, APA PsycINFO, and Embase), with an end date of August 3rd, 2023. Fourteen published studies were included in this review.ResultsTBI patients with depression exhibited distinct changes in diffusion- based white matter fractional anisotropy, with the direction of change depending on the acuteness or chronicity of TBI. Decreased functional connectivity (FC) of the salience and default mode networks was prominent alongside the decreased volume of gray matter within the insular, dorsomedial prefrontal, and ventromedial prefrontal cortices. Seven studies reported the correlation between observed neuroimaging and depression outcomes. Of these studies, 42% indicated that FC of the bilateral medial temporal lobe subregions was correlated with depression outcomes in TBI.DiscussionThis systematic review summarizes existing neuroimaging evidence and reports brain regions that can be leveraged as potential treatment targets in future studies examining depression post-TBI.

Сучасне розуміння етіопатогенезу дегенеративної хвороби дисків поперекового відділу у осіб дитячого віку. Освітлення ключових аспектів і перспектив

Low back pain is the most common complaint among people of any age, and degenerative disc disease (DHD) is the most common cause. Low back pain due to lumbar spondylolysis in adolescent athletes ranges from 8.8% to 47%. Features of the structure of intervertebral discs, a combination of genetic, mechanical, metabolic, and inflammatory factors create conditions for the development of degenerative changes in the vertebral motor segment, especially in intervertebral discs. The results of pathomorphological and magnetic resonance imaging studies show that degenerative changes in discs begin in childhood. Individual publications present data on the formation of a protrusion, even hernias occur in teenagers. Some publications have shown the effectiveness of drugs containing chondrocyte substitutes, indicating that early diagnosis of degenerative changes in the discs will allow timely treatment and secondary preventive measures. Further detailed research is needed to study the features of the development of degenerative changes in the discs in adolescents using imaging methods, taking into account the most common etiopathogenetic factors.

A Functional Magnetic Resonance Imaging Study of Phrase Structure and Subject Island Violations.

In principle, functional neuroimaging provides uniquely informative data in addressing linguistic questions, because it can indicate distinct processes that are not apparent from behavioral data alone. This could involve adjudicating the source of unacceptability via the different patterns of elicited brain responses to different ungrammatical sentence types. However, it is difficult to interpret brain activations to syntactic violations. Such responses could reflect processes that have nothing intrinsically related to linguistic representations, such as domain-general executive function abilities. To facilitate the potential use of functional neuroimaging methods to identify the source of different syntactic violations, we conducted a functional magnetic resonance imaging experiment to identify the brain activation maps associated with two distinct syntactic violation types: phrase structure (created by inverting the order of two adjacent words within a sentence) and subject islands (created by extracting a wh-phrase out of an embedded subject). The comparison of these violations to control sentences surprisingly showed no indication of a generalized violation response, with almost completely divergent activation patterns. Phrase structure violations seemingly activated regions previously implicated in verbal working memory and structural complexity in sentence processing, whereas the subject islands appeared to activate regions previously implicated in conceptual-semantic processing, broadly defined. We review our findings in the context of previous research on syntactic and semantic violations using ERPs. Although our results suggest potentially distinct underlying mechanisms underlying phrase structure and subject island violations, our results are tentative and suggest important methodological considerations for future research in this area.