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Most superconductors have an isotropic, single component order parameter and are well described by the standard (BCS) theory for superconductivity. Unconventional, multiple-component superconductors are exceptionally rare and are much less understood. Here, we combine scanning tunneling microscopy and angle-resolved macroscopic transport for studying the candidate chiral superconductor, 4Hb-TaS2. We reveal quasi-periodic one-dimensional modulations in the tunneling conductance accompanied by two-fold symmetric superconducting critical field. The strong modulation of the in-plane critical field, Hc2, points to a nematic, unconventional order parameter. However, the imaged vortex core is isotropic at low temperatures. We suggest a model that reconciles this apparent discrepancy and takes into account previously observed spontaneous time-reversal symmetry breaking at low temperatures. The model describes a competition between a dominating chiral superconducting order parameter and a nematic one. The latter emerges close to the normal phase. Our results strongly support the existence of two-component superconductivity in 4Hb-TaS2 and can provide valuable insights into other systems with coexistent charge order and superconductivity.
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The Kondo effect, deriving from a local magnetic impurity mediating electron-electron interactions, constitutes a flourishing basis for understanding a large variety of intricate many-body problems. Its experimental implementation in tunable circuits has made possible important advances through well-controlled investigations. However, these have mostly concerned transport properties, whereas thermodynamic observations - notably the fundamental measurement of the spin of the Kondo impurity - remain elusive in test-bed circuits. Here, with a novel combination of a 'charge' Kondo circuit with a charge sensor, we directly observe the state of the impurity and its progressive screening. We establish the universal renormalization flow from a single free spin to a screened singlet, the associated reduction in the magnetization, and the relationship between scaling Kondo temperature and microscopic parameters. In our device, a Kondo pseudospin is realized by two degenerate charge states of a metallic island, which we measure with a non-invasive, capacitively coupled charge sensor. Such pseudospin probe of an engineered Kondo system opens the way to the thermodynamic investigation of many exotic quantum states, including the clear observation of Majorana zero modes through their fractional entropy.
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OBJECTIVE: Post-operative bleeding is one of the most common and severe complications of turbinate surgery. This study compared post-operative bleeding following partial turbinectomy, submucosal turbinate reduction and endoscopic turbinoplasty. METHODS: Post-operative bleeding was assessed in patients who underwent inferior turbinate intervention by partial turbinectomy, submucosal turbinate reduction or endoscopic turbinoplasty between January 2016 and November 2017 and had completed at least one month of follow up. RESULTS: Of 1035 patients who underwent inferior turbinate surgery during the study period, 751 were included. Of these, 56 (7.5 per cent) presented to the emergency room with post-operative bleeding; 31 (8.4 per cent) had undergone partial turbinectomy, 19 (10.7 per cent) had undergone submucosal turbinate reduction and 6 (3.0 per cent) had undergone endoscopic turbinoplasty. The odds ratio of requiring an intervention to control bleeding was significantly lower in the endoscopic turbinoplasty group than in the submucosal turbinate reduction group (odds ratio = 3.26, 95 per cent confidence interval = 1.02-10.43). CONCLUSION: Endoscopic turbinoplasty had the lowest rate of post-operative bleeding and the lowest rate of patients requiring intervention.
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Obstrucción Nasal , Rinoplastia , Endoscopía/efectos adversos , Humanos , Hipertrofia/cirugía , Obstrucción Nasal/etiología , Obstrucción Nasal/cirugía , Hemorragia Posoperatoria/complicaciones , Hemorragia Posoperatoria/etiología , Rinoplastia/efectos adversos , Resultado del Tratamiento , Cornetes Nasales/cirugíaRESUMEN
Despite their partial ionic nature, many layered diatomic crystals avoid internal electric polarization by forming a centrosymmetric lattice at their optimal van-der-Waals stacking. Here, we report a stable ferroelectric order emerging at the interface between two naturally-grown flakes of hexagonal-boron-nitride, which are stacked together in a metastable non-centrosymmetric parallel orientation. We observe alternating domains of inverted normal polarization, caused by a lateral shift of one lattice site between the domains. Reversible polarization switching coupled to lateral sliding is achieved by scanning a biased tip above the surface. Our calculations trace the origin of the phenomenon to a subtle interplay between charge redistribution and ionic displacement, and provide intuitive insights to explore the interfacial polarization and its unique "slidetronics" switching mechanism.
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OBJECTIVE: Post-surgical bleeding after tonsillectomy occurs in 2-7 per cent of cases. This study examined whether heart rate and haematocrit changes are associated with the amount of bleeding. METHOD: In this retrospective analytical study, data were collected from the medical charts of patients admitted with post-surgical bleeding. RESULTS: Over the course of 10 years, there were 218 cases of post-operative bleeding in children aged under 18 years. There was a significant increase in heart rate after the bleeding had started, and a significant decrease in both haemoglobin and haematocrit levels (p < 0.05). There was no significant correlation between the differences in haemoglobin and haematocrit and changes in heart rate. CONCLUSION: No correlation was found between the differences in haemoglobin and haematocrit levels and the changes in heart rate from before the surgery to after the bleeding had started. The monitoring of paediatric patients' heart rate after tonsillectomy surgery solely for the purpose of predicting acute blood loss is therefore discouraged.
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Hemodinámica/fisiología , Hemorragia Posoperatoria/fisiopatología , Tonsilectomía/efectos adversos , Adenoidectomía/efectos adversos , Niño , Femenino , Frecuencia Cardíaca/fisiología , Hematócrito , Hemoglobinas/metabolismo , Humanos , Masculino , Hemorragia Posoperatoria/etiología , Estudios Retrospectivos , Tonsilitis/fisiopatología , Tonsilitis/cirugíaRESUMEN
This study was performed to test a protocol for trans-implant treatment of chronic recurrent maxillary sinusitis (CRS), via implants with an internal removable sealing screw. The appropriate indications for treatment, optimal number of treatment sessions, and general schedule of treatment and follow-up were assessed. This was a retrospective study of 31 patients with CRS who were managed with trans-implant lavage. Of these patients, 28 (referred for a sinus elevation procedure) underwent a simultaneous implantation procedure and treatment of the sinusitis. Three patients received treatment for sinusitis via an already existing implant. The suggested sinusitis treatment protocol includes the drainage of pus through the punctured sinus floor and three sessions of antral irrigation/lavage, four cone beam computed tomography scans, and four transnasal endoscopic observations. The suggested combined protocol includes the simultaneous evaluation of the implant status and the sinusitis treatment results on days 30 and 60 after surgery. Of the 31 patients, 28 (90%) had complete relief of most of their symptoms (nasal obstruction/discharge, anosmia/hyposmia) up to day 30 postoperative. Follow-up nasal endoscopy demonstrated no evidence of active sinus disease. Twenty-seven implants were well-osseointegrated and were still in use for prosthetic purposes. In one case, the implantation failed because of poor bone quality. For the remaining 30 cases, both clinical and radiological results showed stability of the implants and no CRS recurrence during the whole follow-up period. The dental implant with an internal central port and an integral sealing screw may be used for drainage, irrigation, observation, and further treatment of the maxillary sinus in cases of CRS.
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Implantes Dentales , Sinusitis Maxilar , Elevación del Piso del Seno Maxilar , Sinusitis , Implantación Dental Endoósea , Humanos , Seno Maxilar/cirugía , Estudios RetrospectivosRESUMEN
OBJECTIVE: Tracheal mucosal damage is a well-known complication of endo-tracheal intubation and animal models are essential for studying the underlying cellular injury cascade. The novel rat model described here is based on retrograde intubation via tracheotomy and suture fixation of the tube. It aims to simulate the common clinical scenario of tube-related airway damage due to long term intubation. STUDY DESIGN: Prospective randomized control pilot study. METHODS: Male Sprague-Dawley were randomly assigned into two groups: control (no intubation, nâ¯=â¯10), one week of intubation (nâ¯=â¯13). The animals were then euthanized and the trachea was sent for histological analysis. Epithelial damage, mucosal thickness, mucosal gland hypertrophy and fibrosis were reviewed. RESULTS: Intubation procedure survival rate was 84.6% (11/13) and 100% in the control (10/10). The damaged ciliary mechanism was a common finding in the intubated group compared to the preserved normal ciliary architecture in almost all control rats. Average tracheal mucosal thickness was 119.0⯱â¯21.8⯵m for the control group and 254.6⯱â¯22.8⯵m for the intubated group, (pâ¯<â¯0.001). The ciliary damage score was 1.00⯱â¯0.02 in the intubated group, and 0⯱â¯0.02 in the control group. (pâ¯<â¯0.001). The (objective) average total tracheal mucosal gland area was 19,530⯱â¯24,606 in the intubated group and 10,031⯱â¯23,461 in the control group (pâ¯<â¯0,05). Collagen deposition seems higher in the intubated trachea compared to the control. CONCLUSIONS: We describe a novel rat-based animal model for simulating tracheal mucosal damage following long term intubation. This animal model is easy to carry out, reproducible and involves containable animal mortality rates. LEVEL OF EVIDENCE: I.
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Intubación Intratraqueal/efectos adversos , Mucosa Respiratoria/lesiones , Tráquea/lesiones , Tráquea/patología , Animales , Cilios/patología , Colágeno/metabolismo , Modelos Animales de Enfermedad , Fibrosis , Distribución Aleatoria , Ratas Sprague-Dawley , Mucosa Respiratoria/patologíaRESUMEN
INTRODUCTION: Deep vein thrombosis of the upper-extremity (ueDVT) is often caused by trauma to the subclavian vein, central venous line and hypercoagulation disorders. CASE REPORT: We present a case of a ueDVT due to retrosternal goiter compressing the right brachiocephalic vein. Low molecular weight heparin was initiated subcutaneously and fluid was aspirated from the thyroid cyst causing an immediate improvement. Cytology detected no malignancy. At eight-month follow-up, the patient showed complete resolution of her symptoms. DISCUSSION: In general, the optimal treatment should include removal of the compressing thyroid. In co-morbid patients and a dominant thyroidal cyst, thyroid aspiration may be sufficient.
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Venas Braquiocefálicas/diagnóstico por imagen , Bocio Subesternal/diagnóstico por imagen , Trombosis de la Vena/etiología , Anciano de 80 o más Años , Anticoagulantes/uso terapéutico , Femenino , Bocio Subesternal/complicaciones , Heparina de Bajo-Peso-Molecular/uso terapéutico , Humanos , Paracentesis , Tomografía Computarizada por Rayos X , Ultrasonografía Doppler en Color , Trombosis de la Vena/diagnóstico por imagen , Trombosis de la Vena/tratamiento farmacológicoRESUMEN
OBJECTIVE: Laryngotracheal damage is a well-described complication of endotracheal intubation and animal models are essential for studying the underlying cellular injury cascade. This novel rat model is based on transoral intubation and aims to simulate the common clinical scenario of tube-related airway damage. METHODS: Prospective randomized control pilot study. 28 male Sprague-Dawley were randomly assigned into three groups: control, 3-h' intubation and 6-h' intubation. The animals were then euthanized and their laryngotracheal complexes sent for histological analysis. Epithelial damage, mucosal thickness and mucosal gland hypertrophy were reviewed. RESULTS: Total of 13 control animals and 15 intubated animals. 10 intubated animals survived the study protocol. Loss of epithelial surface architecture including damage to the microscopic ciliary mechanism was a common feature amongst all intubated animals. Average mucosal thickness of the larynx (including vocal cords and subglottic area) was 143⯱â¯88⯵m for control rats, 315⯱â¯101⯵m for rats intubated 3â¯h and 574⯱â¯174⯵m for rats intubated 6â¯h .This was a statistically significant difference. Average mucosal gland hypertrophy in the laryngeal subsite was 0.41⯱â¯0.5 in control rats, 1.4⯱â¯0.5 in rats intubated 3â¯h and 2.0⯱â¯0.0 for rats intubated 6â¯h (statistically significant difference). There was a clear difference between three and 6â¯h of intubation with poorer mucosal injury parameters for longer intubation. CONCLUSIONS: We describe a novel rat-based animal model for simulating airway mucosal damage following transoral intubation. This animal model is easy to carry out, reproducible and involves containable animal mortality rates.
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Intubación Intratraqueal/efectos adversos , Laringe/lesiones , Modelos Animales , Ratas Sprague-Dawley , Tráquea/lesiones , Animales , Laringe/patología , Masculino , Proyectos Piloto , Estudios Prospectivos , Distribución Aleatoria , Ratas , Tráquea/patologíaRESUMEN
We study a charge two-channel Kondo model, demonstrating that recent experiments [Z. Iftikhar et al, Nature (London) 526, 233 (2015)] realize an essentially perfect quantum simulation-not just of its universal physics, but also nonuniversal effects away from the scaling limit. Numerical renormalization group (RG) calculations yield conductance line shapes encoding RG flow to a critical point involving a free Majorana fermion. By mimicking the experimental protocol, the experimental curve is reproduced quantitatively over 9 orders of magnitude, although we show that far greater bandwidth/temperature separation is required to obtain the universal result. Fermi liquid instabilities are also studied: In particular, our exact analytic results for nonlinear conductance provide predictions away from thermal equilibrium, in the regime of existing experiments.
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Surface codes have emerged as promising candidates for quantum information processing. Building on the previous idea to realize the physical qubits of such systems in terms of Majorana bound states supported by topological semiconductor nanowires, we show that the basic code operations, namely projective stabilizer measurements and qubit manipulations, can be implemented by conventional tunnel conductance probes and charge pumping via single-electron transistors, respectively. The simplicity of the access scheme suggests that a functional code might be in close experimental reach.
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Comparing high-resolution specific heat and thermal expansion measurements to exact finite-size diagonalization, we demonstrate that Cs(2)CoCl(4) for a magnetic field along the crystallographic b axis realizes the spin-1/2 XXZ chain in a transverse field. Exploiting both thermal as well as virtual excitations of higher crystal-field states, we find that the spin chain is in the XY limit with an anisotropy J(z)/J[perpindicular] ≈ 0.12, substantially smaller than previously believed. A spin-flop Ising quantum phase transition occurs at a critical field of µ(0)H(b)(cr) ≈ 2 T before around 3.5 T the description in terms of an effective spin-1/2 chain becomes inapplicable.
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Introducción: Los angiomiolipomas renales son poco frecuentes en la actividad urológica. La linfangioleiomiomatosis es una rara enfermedad pulmonar que afecta mayoritariamente a mujeres en edad reproductiva. La Esclerosis Tuberosa afecta a diversos órganos, incluyéndose entre sus presentaciones, estas dos entidades. Material y método: Se revisan de forma retrospectiva los pacientes atendidos en nuestro centro, haciendo referencia a tres casos representativos de la enfermedad. Se expone su manejo clínico y Resultados: Asimismo se realiza una revisión de la literatura indexada, que nos permita establecer un protocolo de actuación. Resultados: Entre 1990 y 2004, han sido atendidos 8 pacientes con angiomiolipoma renal. 5 mujeres (62%) y 3 hombres (38%). La media de edad es de 52,3 años (29-69). En 3 pacientes (todas mujeres) se diagnosticó también linfangioleiomiomatosis. Conclusiones: La enfermedad de Bourneville es poco frecuente. Los angiomiolipomas que se asocian, suelen ser múltiples, bilaterales, tendentes al crecimiento y requieren más intervenciones. El diagnóstico precoz permite prevenir futuras complicaciones mediante vigilancia, embolización arterial selectiva o cirugía conservadora. Es importante el tamaño y la presencia de síntomas para decidir la mejor terapia. Las pacientes jóvenes con linfangioleiomiomatosis pulmonar deben ser advertidas del uso de preparados estrogénicos y evitar embarazos
Introduction: Renal angiomyolipomas are not very frequent in urologic activities. Pulmonary lymphangioleiomyomatosis is a rare disease that occurs mainly in women of reproductive age. Tuberous sclerosis shows lesions to different organs, including these both entities. Material and method: We retrospectively analyze patients treated in our center. Three most representatives cases are reported. An indexed literature review is done, in order to establish a clinical protocol to manage these kinds of patients. Resultados: Between 1990 and 2004, eight patients have been attended with an angiomyolipoma renal diagnostic. Five women (62%) and three men (38%). Medium age is 52,3 y (29-69). In 3 of them (all women), it was also done a diagnostic of pulmonary lymphangioleiomyomatosis. Conclusions: Bourneville syndrome is not very frequent. Associated angiomyolipomas usually are multiple, bilateral, with tender to grow and require more interventions. Previous diagnostic let us prevent future complications with vigilance, selective arterial embolization and nephron-spare surgery. Tumour size and the presence of symptoms are more decisive to decide best therapy alternative. Young patients with pulmonary lymphangioleiomyomatosis should be advise against pregnancy and the use of preparations containing estrogens
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Femenino , Adulto , Persona de Mediana Edad , Humanos , Angiolipoma/patología , Linfangiomioma/patología , Esclerosis Tuberosa/patología , Neoplasias Renales/patología , Neoplasias Pulmonares/patología , Embolización TerapéuticaAsunto(s)
Obstrucción de la Arteria Renal/cirugía , Arteria Renal/cirugía , Lesión Renal Aguda/etiología , Adolescente , Arteriosclerosis , Implantación de Prótesis Vascular , Femenino , Humanos , Hipertensión Renovascular/etiología , Arteria Ilíaca/trasplante , Obstrucción de la Arteria Renal/complicacionesRESUMEN
Recently, the superficial musculoaponeurotic system (SMAS) was found to be a composite tissue comprising collagen, elastic fibers, and fat cells in an extracellular viscous matrix. Both SMAS and facial skin tissues exhibit viscoelastic properties, but SMAS tissue has delayed stress relaxation. As a consequence, SMAS is viewed as a firmer elastic foundation for the more viscous facial skin. In some patients, a slackening effect of SMAS tissue takes place over a period ranging from weeks to months after tightening. To determine the relative quantity of viscoelastic components and better understand their biomechanical behavior, a quantitative morphometric study of the elastic and collagen fibers in the SMAS and facial skin was conducted. Thirty-four SMAS preparations were taken from 17 patients during either primary face lift operations (12 women) or reoperative face lift procedures (4 women, 1 man), which were performed 4 to 9 months after the original surgery, to examine the elastin and collagen content. For comparison, preauricular skin was also gathered from these patients. The specimens were stained with Weigert's staining to identify elastin and collagen fibers. Using a computerized morphometric analysis, 100 fields of each SMAS and skin specimen were examined. According to our findings, the average percentage of elastin and collagen fibers in SMAS and facial skin was as follows: (1) the percentage of elastin fibers in the SMAS was 4.71 +/- 1.2 (standard error of mean +/- 0.0291); (2) the percentage of elastin fibers in the skin was 6.1 +/- 1.8 (standard error of mean +/- 0.0436); (3) The percentage of collagen fibers in the SMAS was 38.7 +/- 5.9 (standard error of mean +/- 0.1430); and (4) the percentage of collagen fibers in the skin was 48.47 +/- 6.96 (standard error of mean +/- 0.1688). A statistical significance of p < 0.0001 was demonstrated between the collagen and elastin groups. A different percentage of elastin and collagen fibers was found among the 17 patients and within each of them separately. Neither gender nor age differences were found regarding elastin and collagen fiber content. No statistical differences were demonstrated between specimen sources, i.e., whether the operations were primary or reoperative face lift procedures. Findings from previous studies indicate that the cheek has two viscoelastic layers, the skin and the SMAS. The proportional similarity in average percentages of elastin and collagen in SMAS and facial skin cannot explain the relatively delayed stress relaxation effect of the SMAS. Therefore, the fat cells that are found exclusively in the SMAS probably lend a certain degree of firmness to this layer and play a significant role in the long-term efficacy of SMAS surgery.
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Adipocitos , Colágeno/análisis , Elastina/análisis , Músculo Esquelético/química , Músculo Esquelético/fisiología , Fenómenos Fisiológicos de la Piel , Piel/química , Adulto , Anciano , Diagnóstico por Computador , Elasticidad , Cara , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
It has previously been shown that immunization with pathogenic anti-DNA idiotypes (Ids; e.g. 16/6 Id) leads to the induction of experimental system lupus erythematosus (SLF) in naive mice. The disease is characterized by serological (e.g. anti-double-strand DNA), clinical (elevation of erythrocyte sedimentation rate, leukopenia and proteinuria) and histological (immune complex deposition in kidneys) parameters. To determine whether the 16/6 Id carrying anti-DNA antibodies has unique pathogenic ability, in the current study we have employed diverse sources of anti-DNA antibodies to induce experimental SLE. An IgM anti-DNA antibody lacking the 16/6 Id was able to induce the production of the serological markers of experimental SLE, but not the clinico-histological findings. Furthermore, an IgA anti-DNA (16/6 Id derived from the serum of a patient with celiac disease was very effective in inducing the whole presentation of experimental SLE. Other anti-DNA antibodies failed to induce the autoimmune condition. Combined with our previous experience, the current study points to the diverse potential of various anti-DNA antibodies to induce SLE. The 16/6 Id is only one of a list of the potent pathogenic anti-DNA Ids. These facts may explain in part the diversity of clinical presentations of SLE, including asymptomatic subjects who carry high serum titers of anti-DNA antibodies.
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Anticuerpos Antinucleares/inmunología , Anticuerpos Antinucleares/toxicidad , ADN/inmunología , Lupus Eritematoso Sistémico/inducido químicamente , Animales , Anticuerpos Antinucleares/clasificación , Ratones , Ratones Endogámicos BALB CRESUMEN
Gaucher's disease (GD) is associated with hyperactivity of the immune system, which manifests by polyclonal hypergamma-globulinemia and an increased incidence of monoclonal gammopathies in GD patients. We analyzed sera of 43 patients with GD for the presence of autoantibodies against 14 autoantigens. The results demonstrated a significant increase in the incidence of all autoantibodies tested, ranging from 11% for anti-RNP, pyruvate dehydrogenase (PDH), and DNA antibodies to 57% for rheumatoid factor. The autoantibodies were of all three isotypes, namely, IgG, IgM, and IgA. There was no correlation between the levels of immunoglobulins in the serum and the titer of autoantibodies found. Immunization of naive mice with a pool of purified anti-DNA antibodies form GD patients did not result in induction of experimental systemic lupus erythematosus (SLE), suggesting that they may represent natural autoantibodies that are not pathogenic. In conclusion, we found high titers of natural, polyspecific, nonpathogenic autoantibodies in the sera of GD patients.
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Autoanticuerpos/sangre , Enfermedad de Gaucher/inmunología , Adolescente , Adulto , Animales , Anticuerpos Antinucleares/toxicidad , Especificidad de Anticuerpos , Autoanticuerpos/biosíntesis , Autoanticuerpos/clasificación , Enfermedades Autoinmunes/etiología , Niño , Preescolar , Femenino , Enfermedad de Gaucher/sangre , Humanos , Inmunidad Innata , Isotipos de Inmunoglobulinas/sangre , Inmunoglobulinas/biosíntesis , Inmunoglobulinas/sangre , Masculino , Ratones , Ratones Endogámicos BALB C , Persona de Mediana EdadRESUMEN
A novel approach to the enzyme immunoassay of analytes is presented and illustrated by demonstration of an estradiol assay. The assay depends on the competitive binding of estradiol and estradiol-DNP conjugate to immobilized anti-estradiol. The amount of estradiol-DNP bound is inversely proportional to the amount of free estradiol, and is measured through the use of peroxidase-labeled anti-DNP antibodies. The assay gives a dose-response curve from 10 pg/tube to 450 pg/tube and shows satisfactory correlation with radioimmunoassay.