private void AppendFilter(object sender, RoutedEventArgs e)
        {
            PatientDbContext patientDbContext = new PatientDbContext();
            string           val = txtValue.Text;

            dataGrid.ItemsSource =
                patientDbContext
                .Patients
                .Where(i =>
                       i.FirstName.Contains(val) ||
                       i.LastName.Contains(val) ||
                       i.PatientId.Contains(val) ||
                       i.Title.Contains(val) && (
                           i.Created >= dtFromDate.DisplayDate &&
                           i.Created < dtFromDate.DisplayDate
                           )).ToList();

            patientDbContext.Dispose();
        }