Clinical features and surgical management of traumatic acquired isolated superior rectus palsy.

PURPOSE: Isolated acquired superior rectus palsy (ASRP) is extremely rare. The goal of this report is to describe the clinical manifestations and surgical protocols for treatment of isolated traumatic ASRP. DESIGN: Retrospective observational case series. METHOD: Records of patients presenting with traumatic isolated ASRP from 2011 to 2020 were retrospectively reviewed. Variables analyzed included nature of the damage, ocular alignment, ocular motility, binocular vision, fundus photography, imaging and surgical treatment. RESULT: Of the 23,498 strabismus surgeries performed, 16 (0.07%) were identified as being attributable to traumatic isolated ASRP. Iatrogenic injury during orbital/brain tumorectomy was the most common cause for ASRP, followed by injury resulting from a sharp object, blunt instrument, car accident, dog bite, accidental fall and explosion. The main clinical features were hypotropia and deficient supraduction of the affected eye, accompanied by exotropia, extorsion, decreased vision and ptosis. The imaging examination showed the superior orbital wall fracture in 3 cases and superior rectus rupture in 7 cases. Inferior rectus recession and/or superior rectus resection comprised the major surgical procedures employed for these cases. Vertical deviations were reduced from 45.60 ± 17.52 PD preoperatively to 12.20 ± 12.97 PD postoperatively after an average of 22.70 months at follow-up, with a success rate of 50%. CONCLUSION: Traumatic isolated ASRP comprised only 0.07% of cases receiving strabismus surgery at our hospital. Orbital imaging is essential to identify whether muscle rupture, orbital fractures and/or other possible disorders are present. Superior rectus resection and inferior rectus recession represented the most frequently used surgical procedures.

A bulk form Cu-based ferromagnetic semiconductor (La,Ba)(Cu,Mn)SO with the Curie temperature up to 170 K.

We report the ferromagnetism in a new bulk form Cu-based magnetic semiconductor (La,Ba)(Cu,Mn)SO, which is iso-structural to the prototypical iron-based 1111-type superconductor LaFeAsO. Starting from the parent compound LaCuSO, carriers are introduced via the substitutions of La for Ba while spins are introduced via the substitutions of Cu for Mn. Spins are mediated by carriers, which develops into the long range ferromagnetic ordering. The maximum Curie temperature [Formula: see text] reaches up to [Formula: see text] 170 K with the doping levels of 10% Ba and 5% Mn. By comparing to the (La,Sr)(Cu,Mn)SO where Sr and Mn are co-doped into LaCuSO, we demonstrate that negative chemical pressure would suppress the ferromagnetic ordering.

Two superconducting states with broken time-reversal symmetry in FeSe1-xSx.

Iron-chalcogenide superconductors FeSe1-xSx possess unique electronic properties such as nonmagnetic nematic order and its quantum critical point. The nature of superconductivity with such nematicity is important for understanding the mechanism of unconventional superconductivity. A recent theory suggested the possible emergence of a fundamentally new class of superconductivity with the so-called Bogoliubov Fermi surfaces (BFSs) in this system. However, such an ultranodal pair state requires broken time-reversal symmetry (TRS) in the superconducting state, which has not been observed experimentally. Here, we report muon spin relaxation (µSR) measurements in FeSe1-xSx superconductors for 0 ≤ x ≤ 0.22 covering both orthorhombic (nematic) and tetragonal phases. We find that the zero-field muon relaxation rate is enhanced below the superconducting transition temperature Tc for all compositions, indicating that the superconducting state breaks TRS both in the nematic and tetragonal phases. Moreover, the transverse-field µSR measurements reveal that the superfluid density shows an unexpected and substantial reduction in the tetragonal phase (x > 0.17). This implies that a significant fraction of electrons remain unpaired in the zero-temperature limit, which cannot be explained by the known unconventional superconducting states with point or line nodes. The TRS breaking and the suppressed superfluid density in the tetragonal phase, together with the reported enhanced zero-energy excitations, are consistent with the ultranodal pair state with BFSs. The present results reveal two different superconducting states with broken TRS separated by the nematic critical point in FeSe1-xSx, which calls for the theory of microscopic origins that account for the relation between nematicity and superconductivity.

Arbutin Protects Retinal Pigment Epithelium Against Oxidative Stress by Modulating SIRT1/FOXO3a/PGC-1α/ß Pathway.

Age-related macular degeneration (AMD), which is the leading cause of blindness among the elderly in western societies, is majorly accompanied by retinal pigment epithelium (RPE) degeneration. Because of the irreversible RPE cell loss among oxidative stress, it is crucial to search for available drugs for atrophic (dry) AMD. RNA-Seq analysis revealed that genes related to aging and mitochondrial health were differentially expressed under Arbutin treatment, whereas compared to oxidative injury, our study demonstrated that Arbutin substantially abrogated oxidative stress-induced cell senescence and apoptosis linked to intracellular antioxidant enzyme system homeostasis maintenance, restored mitochondrial membrane potential (MMP), and reduced the SA-ß-GAL accumulation in RPE. Furthermore, Arbutin alleviated oxidative stress-mediated cell apoptosis and senescence via activation of SIRT1, as evidenced by the increase of the downstream FoxO3a and PGC-1α/ß that are related to mitochondrial biogenesis, and the suppression of NF-κB p65 inflammasome, whereas rehabilitation of oxidative stress by SIRT1 inhibitor attenuated the protective effect of Arbutin. In conclusion, we validated the results in an in vivo model constructed by NAIO3-injured mice. OCT and HE staining showed that Arbutin sustained retinal integrity in the case of oxidative damage in vivo, and the disorder of RPE cytochrome was alleviated through fundus observation. In summary, our findings identified that oxidative stress-induced mitochondrial malfunction and the subsequent senescence acceleration in RPE cells, whereas Arbutin inhibited TBHP-induced RPE degeneration via regulating the SIRT1/Foxo3a/PGC-1α/ß signaling pathway. These findings suggested that Arbutin is a new agent with potential applications in the development of AMD diseases.

Oxidative stress-induced lncRNA CYLD-AS1 promotes RPE inflammation via Nrf2/miR-134-5p/NF-κB signaling pathway.

Oxidative stress-induced damage to and dysfunction of retinal pigment epithelium (RPE) cells are important pathogenetic factors of age-related macular degeneration (AMD); however, the underlying molecular mechanism is not fully understood. Long noncoding RNAs (lncRNAs) have important roles in various biological processes. In this study, using an oxidative damage model in RPE cells, we identified a novel oxidation-related lncRNA named CYLD-AS1. We further revealed that the expression of CYLD-AS1 was increased in RPEs during oxidative stress. Depletion of CYLD-AS1 promoted cell proliferation and mitochondrial function and protected RPE cells against hydrogen peroxide (H2 O2 )-induced damage. Mechanistically, CYLD-AS1 also regulated the expression of NRF2, which is related to oxidative stress, and NF-κB signaling pathway members, which are related to inflammation. Remarkably, these two signaling pathways were mediated by the CYLD-AS1 interactor miR-134-5p. Moreover, exosomes secreted by CYLD-AS1 knockdown RPE cells had a lower proinflammatory effect than those secreted by control cells. In summary, our study revealed that CYLD-AS1 affects the oxidative stress-related and inflammatory functions of RPE cells by sponging miR-134-5p to mediate NRF2/NF-κB signaling pathway activity, suggesting that targeting CYLD-AS1 could be a promising strategy for the treatment of AMD and related diseases.

Pattern Strabismus in a Tertiary Hospital in Southern China: A Retrospective Review.

Background and objectives: To analyze demographic and clinical features of pattern strabismus patients and assess the relationship among these clinical variables and risk factors. Materials and Methods: Medical records of pattern strabismus patients who had undergone strabismus surgery at our center between 2014 and 2019 were retrospectively reviewed. Data collected included gender, age at onset, age at surgery, refraction, Cobb angle, pre- and post-operative deviations in the primary position, up- and downgaze, angle of ocular torsion, type/amount of pattern, grade of oblique muscle function and presence/grade of binocular function. To verify the clinical significance of the Cobb angle, 666 patients who had undergone surgery within one week after ocular trauma between 2015 and 2021 were enrolled as controls. Results: Of the 8738 patients with horizontal strabismus, 905 (507 males and 398 females) had pattern strabismus, accounting for 10.36%. Among these 905 patients, 313 showed an A-pattern and 592 showed a V-pattern. The predominant subtype was V-exotropia, followed by A-exotropia, V-esotropia and A-esotropia. Over half of these patients (54.6%) manifested an A- or V-pattern in childhood. The overall mean ± SD Cobb angle was 5.03 ± 4.06° and the prevalence of thoracic scoliosis was 12.4%, both of which were higher than that observed in normal controls (4.26 ± 3.36° and 7.8%). Within A-pattern patients, 80.2% had SOOA and 81.5% an intorsion, while in V-pattern patients, 81.5% had IOOA and 73.4% an extorsion. Patients with binocular function showed decreases in all of these percent values. Only 126 (13.9%) had binocular function, while 11.8% of A-pattern and 15.1% of V-pattern patients still maintained binocular function. Pre-operative horizontal deviation was negatively correlated with binocular function (r = −0.223, p < 0.0001), while the grade of oblique muscle overaction was positively correlated with the amount of pattern (r = 0.768, p < 0.0001) and ocular torsion (r = 0.794, p < 0.0001). There were no significant correlations between the Cobb angle and any of the other clinical variables. There were 724 patients (80.0%) who had received an oblique muscle procedure and 181 (20.0%) who received horizontal rectus muscle surgery. The most commonly used procedure consisted of horizontal rectus surgery plus inferior oblique myectomy (n = 293, 32.4%), followed by isolated horizontal rectus surgery (n = 122, 13.4%). Reductions of pattern were 14.67 ± 6.93 PD in response to horizontal rectus surgery and 18.26 ± 7.49 PD following oblique muscle surgery. Post-operative deviations were less in V- versus A-pattern strabismus. Post-operative binocular function was obtained in 276 of these patients (30.5%), which represented a 16.6% increase over that of pre-operative levels. The number of patients with binocular function in V-pattern strabismus was greater than that of A-pattern strabismus (p = 0.048). Conclusions: Of patients receiving horizontal strabismus surgery, 10.36% showed pattern strabismus. In these patients, 54.6% manifested an A- or V-pattern in childhood, and V-exotropia was the most frequent subtype. Pattern strabismus patients showed a high risk for developing scoliosis. Cyclovertical muscle surgery was performed in 724 of these patients (80.0%), and horizontal rectus surgery was effective in correcting relatively small levels of patterns. Binocular function represented an important factor as being involved with affecting the occurrence and development of pattern strabismus.

Clinical Characteristics and Surgical Outcomes of Patients with Congenital Fibrosis of the Superior Rectus Muscle.

INTRODUCTION: Congenital fibrosis of superior rectus muscle (CFSRM) is extremely rare and a difficult condition to manage surgically. The purpose of this report is to summarize the clinical characteristics of patients with CFSRM and analyze the effects of its surgical management. METHODS: Records of nine CFSRM patients were retrospectively reviewed and their clinical features including age, gender, visual acuity, refraction, ocular alignment, ocular motility, surgical method employed and final outcomes were analyzed. RESULTS: All cases were monocular. There were four cases (44.4%) coexistent with fibrosis of the levator palpebrae muscle and three (33.3%) with fibrosis of the superior oblique muscle. Eight cases (88.9%) presented with hypertropia, and one case showed mild hypotropia. Horizontal deviation was presented in six cases (66.7%). Surgical approaches included either superior rectus recession/tenotomy with or without traction suture; superior rectus recession and inferior rectus resection; or adhesion separation of superior rectus and levator palpebrae muscles. Excellent surgical outcomes were obtained in five cases (55.6%), good in two (22.2%), and poor outcomes were reported for two cases (22.2%). One patient (11.1%) underwent a second surgery. CONCLUSION: CFSRM was found to be mainly unilaterally infected, mostly manifesting as hypertropia, and was often associated with fibrosis of the levator palpebrae or superior oblique muscle. Weakening procedures of the superior rectus muscle were the preferred surgical technique. However, success rates were relatively low for CFSRM.

Different Surgical Approaches for treatment of isolated dissociated vertical deviation without inferior oblique overaction.

PURPOSE: To report the surgical results on superior rectus recession (SRR) and inferior oblique anterior transposition (IOAT) for cases with isolated bilateral dissociated vertical deviation（DVD）without inferior oblique overaction (IOOA). METHODS: A retrospective review was conducted for cases with isolated bilateral DVD without IOOA who were surgically treated using either bilateral SRR (SRR group) or IOAT (IOAT group). Pre- and post-operative ocular motility, ocular alignment, amount of DVD and complications were compared between the two groups. RESULTS: Records from 37 cases were reviewed. Preoperative levels of DVD (M ± SD) in the SRR group (N = 18) of 19.88 ± 6.72 prism diopter (PD) in the right eye and 19.54 ± 5.64 PD in the left eye, were reduced to 4.94 ± 7.26 PD and 4.11 ± 3.91 PD respectively after surgery (P＜0.0001 for both). Preoperative levels of DVD (M ± SD) in IOAT group (N = 19) of 15.89 ± 6.35 PD in the right eye and 18.58 ± 9.27 PD in the left eye, were reduced to 3.42 ± 4.49 PD and 3.42 ± 4.88 PD respectively after surgery (P＜0.0001 for both). Inferior oblique (IO) muscle function remained normal after surgery. Overall, outcomes within the SRR group revealed that 10 patients showed a complete resolution of their condition, 6 effective responses and 2 failures. In the IOAT group, 13 patients showed a complete resolution of their condition, 5 effective responses and 1 failure. There were no statistically significant differences between the two groups (Z = 0.48). CONCLUSION: SRR and IOAT were both effective in treating isolated DVD without IOOA with similar satisfactory results obtained for both procedures.

Clinical characteristics and surgical outcomes of isolated inferior rectus palsy.

AIM: As isolated inferior rectus muscle (IRM) palsy represents a rare clinical entity, very limited information is available on this condition. The aim of this report was to elucidate the etiology, clinical characteristics and surgical outcomes of isolated IRM palsy. METHODS: Isolated IRM palsy cases who underwent surgical treatments at the Zhongshan Ophthalmic Center, Sun Yat-sen University, China over the period from January 2008 to June 2019 were reviewed retrospectively. Data evaluated from these cases included their etiology, ocular alignment, ocular motility, surgical procedures and surgical outcomes. RESULTS: A total of 61 patients (40 males, 21 females) were included in this review. Their mean ± SD age was 27.21 ± 16.03 years (range: 2 to 73 years). In these cases, 32 (52.5%) involved traumatic injury, 28 (45.9%) congenital hypoplasia or absence of inferior rectus and 1 (1.6%) with thyroid ophthalmopathy. The right eye was affected in 33 patients (54.1%), the left in 24 patients (39.3%), and both eyes in 4 patients (6.6%). The main clinical presentations consisted of hypertropia of the affected eye, motility limitation in abduction and depression and incyclotropia. After treatment consisting of various surgical approaches, including muscle repair or resection of the affected inferior rectus, recession of ipsilateral superior rectus, elongation of contralateral superior oblique and partial transposition of the horizontal rectus, the isolated IRM palsy was rectified in 49 patients (80.4%) with one surgery, while 11 cases (18.0%) required two surgeries and 1 case (1.6%) needed three surgeries. Finally, 52 patients (85.2%) showed a complete recovery, 6 (9.9%) improved and 3 (4.9%) experienced a surgical failure. CONCLUSION: The main etiologies of isolated IRM palsy involved traumatic injury and developmental events. Overall, surgical outcomes of the various approaches employed were quite effective.

Effect of extraction method on the chemical profiles and bioactivities of soybean hull polysaccharides.

The yields, properties, and bioactivities of polysaccharides extracted by three methods from soybean hulls (SSCPs) were evaluated: hot water extraction (H-SSCP), microwave-assisted ammonium oxalate extraction (A-SSCP), and microwave-assisted sodium citrate extraction (S-SSCP). A-SSCP gave the highest yield of polysaccharides (9.3 ± 0.5%) although all three products had similar physicochemical characteristics and FT-IR spectra. A-SSCP and S-SSCP produced polysaccharides with lower molecular weight distributions and higher total reducing power and scavenging ability for ABTS+• and DPPH• free radicals. Furthermore, the effect of SSCPs on carbon tetrachloride (CCl4)-induced liver injury was investigated in the mice. When compared with H-SSCP and S-SSCP, A-SSCP significantly decreased the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), malondialdehyde (MDA), and reactive oxygen (ROS) to normal (p < .05) and increased the level of glutathione (GSH) to normal (p < .05). A-SSCP was the most effective polysaccharide, yielding an approximately normal hepatic appearance with well-preserved cytoplasm, obvious cell boundaries, with legible nuclei and nucleoli. This study indicates that polysaccharides extracted from soybean hulls via microwave-assisted ammonium oxalate extraction have the potential to be developed as a new functional food contributing to the alleviation of liver damage.

Congenital dysplasia involving both medial and inferior recti: clinical features and surgical outcomes.

AIM: To investigate the clinical features and surgical outcomes of congenital dysplasia involving both inferior recti (IR) and medial recti (MR) muscles. METHODS: A retrospective review was conducted including cases of simultaneous congenital dysplasia of IR and MR that were diagnosed and surgically treated at the Zhongshan Ophthalmic Center, Sun Yat-sen University, China, from July 2009 to November 2019. Ocular motility, ocular alignment at distance (6 m) and near (33 cm) by prism alternating cover test and stereoacuity were assessed in all patients before and after surgery. RESULTS: A total of five patients (four males and one female; three with right eye and two with left eye congenital dysplasia) were included in this review. The patients ranged in age from 10 to 42y (21±13.4y). The main clinical findings were hypertropia and exotropia of the affected eye, along with motility limitations in adduction and depression. Lateral rectus (LR) recession/transposition combined with IR resection was performed in one case. Two scheduled surgeries were performed in four cases, with one involving superior rectus recession and IR resection and the others LR recession and MR resection. Mean±SD pre-surgical exotropia of 51.0±31.11 prism diopter (PD) and hypertropia of 29.20±7.12 PD in the primary position were decreased to 3.6±12.90 and 3.2±10.09 PD, respectively, at two years after surgery, with a success rate of 60% and an under-correction rate of 40%. CONCLUSION: The main clinical features associated with simultaneous MR/IR congenital dysplasia are hypertropia and exotropia of the affected eye along with motility limitations in adduction and depression. Scheduled two-stage surgeries achieved a success rate of 60%.

Drastic improvement of Curie temperature by chemical pressure in N-type diluted magnetic semiconductor Ba(Zn,Co)[Formula: see text]As[Formula: see text].

We report the effect of chemical pressure on the ferromagnetic ordering of the recently reported n-type diluted magnetic semiconductor Ba(Zn[Formula: see text]Co[Formula: see text])[Formula: see text]As[Formula: see text] which has a maximum [Formula: see text] [Formula: see text] 45 K. Doping Sb into As-site and Sr into Ba-site induces negative and positive chemical pressure, respectively. While conserving the tetragonal crystal structure and n-type carriers, the unit cell volume shrink by [Formula: see text] 0.3[Formula: see text] with 15[Formula: see text] Sr doping, but drastically increase the ferromagnetic transition temperature by 18[Formula: see text] to 53 K. Our experiment unequivocally demonstrate that the parameters of Zn(Co)As[Formula: see text] tetrahedra play a vital role in the formation of ferromagnetic ordering in the Ba(Zn,Co)[Formula: see text]As[Formula: see text] DMS.

Etiology and Clinical Features of Diplopia in South China: Analysis of 303 Cases.

PURPOSE: To provide a new classification system for diplopia and evaluate the etiology and clinical features of diplopia subtypes in south China. METHODS: In this retrospective study, all patients presenting with diplopia over the period from 2012 to 2014 in south China were reviewed. Patients were categorized into 3 groups according to their extraocular muscle (EOM) dysfunction: single EOM (sEOM), multiple EOMs (mEOMs), and a comitant strabismus group. Clinical data evaluated included age, sex, medical history, etiology and duration of diplopia, ocular alignment, and ocular motility. RESULTS: A total of 303 patients were enrolled. The most common type of EOM dysfunction was sEOM (158 cases, 52.1%), followed by mEOMs (n = 119, 39.3%), and finally the comitant strabismus group (n = 26, 8.6%). Overall, the most common cause of diplopia involved orbital diseases. Within the sEOM group, microangiopathy (n = 42, 26.6%) and trauma (n = 41, 25.9%) were the major etiologies, with the lateral rectus (LR) (n = 86, 54.4%) being the most frequently involved. There were 12 (4.0%) patients who were considered as nasopharyngeal carcinoma (NPC)-associated diplopia (10 caused by radiation neuropathy following radiation therapy). Thyroid associated ophthalmopathy (TAO, 56 cases, 47.1%) was the predominant etiology found in the mEOMs group. Acute acquired comitant esotropia (AACE, 14 cases, 53.9%) was the most common etiology in the comitant strabismus group. CONCLUSIONS: This new classification system for assessing diplopia as based on EOM dysfunction represents an easy-to-follow approach that can be readily adapted for the clinical use. While microangiopathy and trauma represent common etiologies of diplopia, both orbital diseases and NPC-associated diplopia also warrant special attention when assessing diplopia within patients in south China.

Supramaximal Horizontal Rectus Recession-Resection Surgery for Complete Unilateral Abducens Nerve Palsy.

Purpose: To review the surgical procedures and outcomes of supramaximal horizontal rectus recession-resection surgery for abduction deficiency and esotropia resulting from complete unilateral abducens nerve palsy. Methods: A total of 36 consecutive cases diagnosed as complete abducens nerve palsy, receiving supramaximal medial rectus recession (8.5 ± 1.4 mm, range: 6-10) combined with a supramaximal lateral rectus resection (11.1 ± 1.7 mm, range: 8-14) as performed over the period from 2017 to 2020, were reviewed retrospectively. All surgeries were performed by a single surgeon. Pre- and post-operative ocular motility, ocular alignment, forced duction test, binocular vision, abnormal head posture, and surgical complications were assessed. Results: Of these 36 cases, 23 (63.8%) were followed up for greater than 2 months (Mean ± SD = 8.4 ± 6.0, range: 2-24) after surgery and the collected data was presented. Mean ± SD age of these patients was 41.7 ± 14.4 (range: 12-67) years with 73.9% being female. Trauma (52.2%, 12/23) and cerebral lesions (21.7%, 5/23) were the primary etiologies for this condition. Esodeviation in primary position improved from 55.5 ± 27.2 prism diopters (PD) (range: +25 to +123) to 0.04 ± 7.3 PD (range: -18 to +12) as assessed on their last visit. Pre-operative abduction deficits of -5.6 ± 1.0 (range: -8 to -4) reduced to -2.4 ± 1.4 (range: -4 to 0) post-operatively. The mean dose-effect coefficient of 2.80 ± 1.20 PD/mm (range: 1.07-6.05) was positively correlated with pre-operative esodeviation. Rates of overcorrection and ortho were 69.6 and 26.1%, respectively, on the first day after surgery, while on their last visit the respective levels were 4.3 and 82.6%. Conclusion: Supramaximal horizontal rectus recession-resection surgery is an effective treatment method for complete abduction deficiency. The dose-effect was positively correlated with pre-operative esodeviation. Overcorrection on the first day post-operatively is required for a long-term satisfactory surgical outcome.

Aquaporin-1 down regulation associated with inhibiting cell viability and inducing apoptosis of human lens epithelial cells.

AIM: To investigate the role of Aquaporin-1 (AQP-1) in lens epithelial cells (LECs) and its potential target genes. AQP-1 is specifically expressed in LECs of eyes and is significant for lens homeostasis and transparency maintenance. Herein, AQP-1 expression in LECs was investigated to evaluate its influence on cell survival in association with its potential role in cataract formation. METHODS: LECs were transfected with lentivirus carrying AQP-1 small interfering RNA (siRNA). Real-time polymerase chain reaction (PCR) and Western blotting were conducted to detect AQP-1 expression in LECs from different groups. Meanwhile, cell counting kit-8 (CCK-8) assay and flow cytometry were performed to measure LEC proliferation and apoptosis, respectively. RESULTS: AQP-1 expression was significantly reduced in LECs, both at mRNA and protein levels (P<0.05), after siRNA treatment. Decreased cell viability was detected by CCK-8 assay in LECs with siRNA interference, compared to control cells (P<0.05). The apoptosis rate significantly increased in cells after siRNA interference (P<0.05). CONCLUSION: The decreased cell viability following AQP-1 down regulation is largely due to its induction of apoptosis of LECs. AQP-1 reduction might lead to changes of physiological functions in LECs, which might be associated with the occurrence and development of cataracts.

The synthesis and characterization of 1 1 1 1 type diluted ferromagnetic semiconductor (La(1-x)Ca(x))(Zn(1-x) Mn(x))AsO.

We report the synthesis and characterization of a bulk form diluted magnetic semiconductor, (La(1-x)Ca(x))(Zn(1-y) Mn(y))AsO, with a layered crystal structure isostructural to that of the 1 1 1 1 type Fe-based high-temperature superconductor LaFeAsO and the antiferromagnetic LaMnAsO. With Ca and Mn codoping into LaZnAsO, the ferromagnetic ordering occurs below the Curie temperature T(c) ∼30 K. Taking advantage of the decoupled charge and spin doping, we investigate the influence of carrier concentration on the ferromagnetic ordering state. For a fixed Mn concentration of 10%, T(c) increases from 24 K to 30 K when the Ca concentration increases from 5% to 10%. Further increase of Ca concentration reduces both the coercive field and saturation moment. Muon spin relaxation measurements confirm the ferromagnetically ordered state, and clearly demonstrate that La(1-x)Ca(x))(Zn(1-y) Mn(y))AsO shares a common mechanism for the ferromagnetic exchange interaction with (Ga,Mn)As. Neutron scattering measurements show no structural transition in (La(0.90)Ca(0.10))(Zn(0.90)Mn(0.10)) AsO below 300 K.